Due to the hazy way in which mainstream comic books play with the progression of the time, we almost never see pregnancy storylines. Writers never know how long they are going to be on a series for, and a pregnancy story could take years of real life time to unfold, especially when you only have a few issues a year in which it will happen. There a few occasions where comics have done a superhero pregnancy storyline well, such as with the birth and growth of Franklin Richards. There have also been some terrible ones, like when Ms. Marvel was impregnated by an alternate universe version of her son (don't ask).

But what about supervillains as prospective parents? It has happened more often than you think. Some of the most evil beings in the Marvel & DC Universes have bred, and become fathers and mothers to little supervillains of there own. Their skills as parents might leave something to be desired though.

From the world devouring Galactus, to the Clown Prince of Crime himself. Here are 15 Supervillains You Didn't Know Were Parents.

15. Sinestro

Sinestro was once known as the most powerful member of the Green Lantern Corp. It wasn't until the Guardians looked more closely at his home sector that the truth of Sinestro was revealed. He had secretly been ruling his home world of Korugar as a dictator, punishing those who questioned his rule. Sinestro was stripped of his ring for his crimes and banished to the anti-matter universe. Unbeknownst to the Green Lanterns, Sinestro had left something important on Korugar...

It was revealed in Green Lantern Corps: Recharge #1 that the ring of sector 1417 (where Korugar resides) needed a new bearer. The ring joined with Soranik Natu, a neurosurgeon who, like most citizens of Korugar, despised the Green Lanterns and everything they stood for. She only accepted the ring's power in order to save a patient who she was operating on.

Soranik went on to join the Green Lantern Corp and even became romantically involved with Kyle Rayner. It was later revealed that she was the daughter of Sinestro, who confronted her during the Sinestro Corps War storyline. Despite being an evil despot, Sinestro does have affection for his daughter. He eventually welcomed her into the Sinestro Corp under his leadership.

14. Deathstroke

When the first Teen Titans cartoon was broadcast in 2003, it brought the Titans main villain, Slade (better known in the comics as Deathstroke), into the limelight. Before becoming the main villain in Teen Titans, Slade was best known as being the character whom Deadpool was a rip-off of (at least visually). He's come along way, as he's about to make an appearance the DCEU.

In the comics, Deathstroke has two children who have taken on the identity of The Ravager; the first was Grant Wilson, who followed the villain path like his father. Grant died during a mission where he tried to kill the Teen Titans, but briefly returned as a zombie during the Blackest Night event.

The second child of Deathstroke's to take the identity of the Ravager is Rose Wilson, although she was a member of the Teen Titans. Deathstroke was not aware of Rose's existence until she was in her teens. After leaving her in the Titan's care for a while, Deathstroke kidnapped Rose and put her through the training from hell. He injected her with drugs that give her enhanced abilities similar to his own, but causes her to lose her mind in the process.

As a final test of her worth, Rose gouges out one of her eyes to match her father.

13. Thanos

Along with being the guy who you wait past the credits to see, Thanos is also a conqueror of galaxies. During his long lifespan, Thanos has had many children who have passed away under his care. There exists another child of Thanos who managed to survive due to being hidden away from him.

Thanos had a child with a member of the Inhumans who managed to escape his captivity and made her way back to her home world. She would give birth to Thane, the son of Thanos. When Thanos discovered the child's existence, he went on a crusade throughout the universe, wiping out entire civilisations in his search for Thane.

Thane had been kept hidden on earth, and had never undergone Terrigenesis (the process which gives Inhumans their power). After being caught in a Terrigen bomb that activated his powers, Thane became one of the most powerful beings in the Marvel Universe. He used his newfound power to supplant Thanos and take his place as ruler of the Universe, albeit a much nicer one. Thane lacks his father's romantic obsession with Death, and seeks to undo a lot of the damage that Thanos has done.

12. Carnage

Considering the fact that Carnage is an evil red blob who attaches itself to serial killers so that it can murder people more efficiently, its hard to imagine it ever giving birth. That being said, Carnage himself was born from Venom, as the symbiotes breed on their own without requiring a mate.

The third main symbiote is called Toxin, who, unlike the other two, is a hero. When Toxin was about to be born, Carnage wanted to kill him straight away, so as not to have any competition. When Venom discovered that Carnage was going to give birth, he protected his grandchild from death, as he thought this new symbiote could be an ally. Carnage was too weak after giving birth to kill Toxin, allowing him time to bond to the human, Patrick Milligan.

Unlike Venom and Carnage, who bonded to evil individuals, Toxin was bound to a police officer. With this more positive influence, Toxin became a protector of New York City, and even becoming friendly with Spider-Man.

11. Loki

While Tom Hiddleston has no shortage of women who want to have his babies, the actual character of Loki has it a lot harder. It's trickier to get laid when most of the other gods in Asgard despise you. Seeing that none of his fellow gods were interested, Loki was forced to turn to the mortal world to find a lover. Eventually he succeeded, leading to the birth of Vali Halfling, aka Agamemnon - the son of Loki.

Unlike his father, Vali would go on to have many children. He had so many super-powered offspring that they would go on to form their own team - The Pantheon. The Incredible Hulk would actually become a member of The Pantheon in a story arc that lasted throughout the early nineties.

Vali would go on to make his father proud, however, due to the sheer number of times he has been a thorn in the side of the gods. He doesn't restrict his villainy to the Asgardians either, he has messed with the Egyptian, Hindu and Greek pantheons in his quest for power.

10. Doctor Sivana

One of the main villains of Shazam is the mad scientist Doctor Sivana. Despite looking like Professor. Farnsworth from Futurama, Doctor Sivana has managed to father children. Four of them, in fact, over the course of 75 years of publication and several dimensions of continuity.

Since the original iteration of Doctor Sivana from the Fawcett Comics days, he had four children named Thaddeus, Georgia, Beautia and Magnificus. Thaddeus and Georgia took after their father, and were scientists who were obsessed with defeating DC's Captain Marvel family, with Georgia becoming one of the main villains for Mary Marvel.

Unlike their other siblings who took after their father, Beautia and Magnificus do not resemble him in the slightest. As her name implies, Beautia is a stunningly beautiful woman and Magnificus is a strong, handsome man. The two of them would initially oppose the Marvel family, but would go on to befriend them, and turn on their wicked father.

9. Galactus

You would think that being a colossal, planet-eating monster would impair the love life of Galactus. Well, you would be right. There aren't many opportunities to get a hot chick's phone number while you are preparing to wipe out her civilization to sate your cosmic hunger.

Luckily for Galactus, he didn't need a lady planet-eater in order to conceive a child. Along with keeping him alive, the life energy of the planets that Galactus eats also goes towards feeding a cosmic-tapeworm inside himself. This energy went on to form Galacta, the estranged teenage daughter of Galactus. Luckily, no one needed to call Maury Povich to verify if he was, indeed, the father. The power Cosmic gives you the purple armour and pointy hat as a default setting.

Despite eating planets and killing countless lifeforms, Galactus is actually a pretty decent dad. When Galacta was considering killing herself with the Ultimate Nullifier (the same weapon used by the Fantastic Four to threaten Galactus when he first came to Earth), Galactus returned and stopped her. He revealed that Galacta is now pregnant with a cosmic tapeworm herself, convincing her to continue living.

8. Lex Luthor

When he isn't stinking up Batman v Superman: Dawn of Justice, Lex Luthor is the primary villain of Superman in the comics. While most children on this list were born from the coupling of a man and a woman, Lex Luthor decided to have a child with his arch-nemesis... Superman.

When Superman was killed by Doomsday during the Death of Superman story arc, four new characters showed up that claimed to have a connection with him. One of these was Superboy, also known as Conner Kent. With no Superman around to protect the world, Project Cadmus decided to try and make a clone of Superman to try and fill the void (who would also protect their interests). This new version of Superboy had powers based around telekinesis, which mimicked those possessed by Superman.

Superboy had no idea of his true origins, until it was revealed to him that not only was he a clone of Superman, but of Lex Luthor as well. He was the first clone in a line of human and Kryptonian hybrids.

When Superboy died during Infinite Crisis, Lex Luthor genuinely mourned over the loss of his son, even if he was born under very unusual circumstances.

7. Red Skull

Despite giving a great performance in Captain America: The First Avenger, it is unlikely that we will ever see Hugo Weaving return to the role of the Red Skull, due to his personal dislike of his performance. That doesn't mean we won't see another actor play the Red Skull (it wouldn't be too much of a stretch, considering the amount of prosthetics that the role requires). If they wanted to swap out Red Skull for a more visibly appealing character, they could always use his daughter, Sinthea Shmidt.

Due to his desire for a male heir, Red Skull would try for a son with a washerwoman. He would instead get Sinthea, a daughter whom he considered unfit to take his position. Sinthea would go on to be raised by Red Skull's ally, Susan Scarbo, who would groom her for leadership of the villain team - The Sisters of Sin.

In recent years, Sinthea has been a constant thorn in the side of Captain America and S.H.I.E.L.D, and has even opposed her own father. Despite her father's misgivings, Sinthea has proved herself more than equal to the task of taking the Red Skull's place.

6. Mastermind

When Mastermind was first introduced in The X-Men #4, he was a run of the mill supervillain that showed no signs of the awesomeness that he would later bring to the series. He was initially a member of the Brotherhood of Evil Mutants, with the mutant ability to project illusions. He would be a recurring minor foe of the X-Men until the epic Dark Phoenix Saga, where he took centre stage. Mastermind used his powers to seduce Jean Grey and to corrupt the mighty Phoenix force into a being of evil, who threatened to wipe out all life in the universe.

Mastermind eventually died due to the mutant-killing disease known as The Legacy Virus. It was later revealed that he had left three children behind, who have become important characters in the pages of The Uncanny X-Men.

Two of his daughters (Martinique and Regan) would share his powers, take on his codename and become villains of the X-Men. They are essentially two more in a long line of attractive gender swaps of popular X-Men characters (like X-23 and Miss Sinister).

The third daughter (Megan) is Pixie, one of the prominent members of the modern X-Men.

5. Avalanche

While Mastermind belonged to the original iteration of the Brotherhood of Evil Mutants that was led by Magneto, the second version of the group is, perhaps, the more famous one. During the classic Days of Future Past storyline, the Brotherhood of Evil Mutants, led by Mystique, were responsible for killing Senator Robert Kelly. This led to a public backlash against mutants, leading to the creation of the giant robotic Sentinels. When the Sentinels took over the world, nearly all super-powered beings were killed.

A prominent member of the second Brotherhood of Evil Mutants was Avalanche, a mutant with the ability to cause seismic quakes in the earth. Along with being a constant enemy of the X-Men, Avalanche was also a member of Freedom Force, which is essentially the Marvel version of the Suicide Squad.

In Uncanny Avengers #1, it was revealed that Avalanche had a daughter - the evil mutant called Dancing Water. True to her name, Dancing Water is made of water and can control liquid around her. She is a prominent member of the S-Men, an evil team of mutants formed by Red Skull to oppose the X-Men.

4. Grim Reaper

When you think about it, there are quite a few iterations of the Grim Reaper in comic books. You have the sexy goth chick from Sandman, the much less sexy skeleton wearing robes that Thanos is in love with, and in DC, there exists a character called the Black Racer, who is the incarnation of death... on skis. He exists to hunt the New Gods and the bearers of the Speed Force.

In Marvel, there is a villain by the name of the Grim Reaper, he is a long-time villain of The Avengers and is the brother of Wonder Man. Grim Reaper was originally a technology themed villain, until his death. He would go on to be brought back by the Apocalypse Twins and become their Horseman of Death, gaining necromancy powers in the process.

In 2009s Dark Reign series, it was revealed that the Grim Reaper has a daughter named Death Reaper (whom he sired with fellow villain, Nekra). Death Reaper is a magic using supervillain who joined the Zodiac Gang, a group determined to find the Zodiac Key, a powerful magical device.

3. Kraven the Hunter

Kraven the Hunter is a popular recurring Spider-Man villain, who is obsessed with hunting Spider-Man as he considers him a prey worthy of his skills. Kraven was also an occasional member of the Sinister Six, a group obsessed with the downfall of Spider-Man. The most famous Kraven story is The Last Hunt, in which he takes his own life after finally defeating Spider-Man (although this is Marvel we're talking about - he didn't stay dead for long).

It was revealed in The Spectacular Spider-Man #243 in 1997 that Kraven had a son, whom he fathered with an unknown mutant woman. This son would grow up to be Alexei Kravinoff, who had augmented mutant abilities and was a much more dire threat to Spider-Man than his father was. Unlike his father however, he was less concerned with actually killing Spider-Man than he was with just outsmarting him.

Alexei later discovered that he had a half sister, Anastasia Kravinoff, who had also taken the name Kraven the Hunter. She murdered him during the Grim Hunt storyline.

2. Sabretooth

Sabretooth is a long-running villain of both the X-Men and Wolverine. He was one of the original Brotherhood of Evil Mutants that appeared in the first X-Men movie, and has been a popular Marvel villain for a long time. It is due to this popularity that, despite Wolverine cutting off his head with a magic sword that specifically prevents the mutant Healing Factor from working, he still returned from the grave.

In the comics, Sabretooth fathered a child with Mystique, who would go on to become a prominent X-Men villain called Graydon Creed. Despite having two mutants for parents, Graydon Creed was a regular human without powers. He was adopted as a child, and when he learnt that his parents were both mutants, he formed the Friends of Humanity, an anti-mutant organization. He would later take part in the "Gamesmaster's contest", a world-spanning event where super powered beings were given points for killing mutants.

Due to Mystique being his mother, Graydon Creed is also the half-brother of Nightcrawler of the X-Men.

1. The Joker & Harley Quinn

As proven by the massive success of the Suicide Squad movie (despite the poor reviews), audiences love the twisted relationship of The Joker and Harley Quinn. Margot Robbie's portrayal of Quinn has been touted as the best part of Suicide Squad, and there is a strong chance we will get to see a Harley Quinn solo movie.

Despite the overtly sexual relationship between the two, there was never any mention of the Joker and Harley Quinn having a child in the regular DC universe. The issue was finally brought up in Injustice: Gods Among Us: Year Two #13, where Harley Quinn discovers that Black Canary is pregnant while the two are fighting. Harley immediately backs down and relates a story of her own. In this continuity, Harley has a four year old daughter that is being taken care of by her sister. The child is the Joker's, but Harley has kept her existence a secret for fear of the child's life.

Whether this portrayal of Harley as a loving mother, who willingly gave up her child to ensure its safety makes it into the new reboot of the DC universe or the movies still remains to be seen. It's inclusion would go a long way towards redeeming Quinn, and giving her a shot at, some day, becoming a hero.