There are a lot of terrible people in the world of It's Always Sunny in Philadelphia. In most of those cases, those people were terrible before they ever came in contact with the gang at Paddy's Pub. Liam McPoyle, for example, has probably been a pretty unsettling guy his entire life. It's quite literally in his genetics.
On the other hand, Rickety Cricket was doing pretty well before Sweet Dee and the rest of the gang came back into his life. He went on quite a slide straight into the gutter. But Cricket and Liam are awful for entirely different reasons.
LIAM MCPOYLE: The Eye Patch
Having an eye patch was by no means Liam's fault. It was one of many negative results of his disastrous attempted wedding to Maureen Ponderosa. The riot that followed Bill Ponderosa spiking the punch with bath salts played a huge role in Liam losing his eye that day.
But no one forced Liam to get an incredibly creepy eye patch colored to match his skin tone, then paint an even more disturbing fake eye on it.
RICKETY CRICKET: Happily Addicted To All The Drugs
Once Sweet Dee had destroyed Cricket's life to its fullest extent and resigned him to a life on the streets, he turned to drugs to cope. What is he addicted to? Seemingly every possible drug in existence, though he does seem to have a special affinity for PCP.
More than the fact that he won't say no to any drug offered to him, Cricket shows little or no desire to change that, often bribed by the gang to do awful things with small amounts of any drug.
LIAM MCPOYLE: Screwing With The Gang
It doesn't take much to get the gang riled up. At least one, if not all of them, are coming in hot about something, which is often exacerbated by all of them not being on the same side. Nobody seems to know how to rile the gang up the way Liam does.
The McPoyles even faked holding the entire gang hostage at Paddy's at one point, which only took the whole feud up a notch or two. That being said, Charlie seems to hate them the most.
RICKETY CRICKET: Degradation
Thankfully, viewers have never had to see how Cricket makes money in an actual episode. Unfortunately, they have been treated to some disturbingly graphic descriptions of how life goes down on the street for Cricket.
As he got deeper, he became more open about turning to willingly being degraded to finance his life on the street. Cricket even assumed his own father was a trick at one point, describing what he would and would not do with him. And while there's nothing wrong about sex work per se, the kind of work that Cricket does, and how he talks about it, is deeply disturbing.
LIAM MCPOYLE: Wearing Bathrobes Everywhere
One of the creepier foibles about Liam and his immediate family was constantly wearing bathrobes. Honestly, there were only a few places they weren't spotted wearing bathrobes, Liam's failed wedding to Maureen, and at the video store he bought.
Outside of Liam and his siblings, other McPoyles don't seem to be as addicted to what should be a clothing choice reserved for the home.
RICKETY CRICKET: Willing To Kill Someone
As an experienced street rat, Rickety Cricket has proven to be willing to do virtually anything to debase himself. That includes murder.
When the gang was trying to figure out if the guy on their roof was going to kill himself and if they should do something about it, they came to the conclusion he should die. Dennis enlisted the help of Cricket to speed the process along, which he did not question in the least.
LIAM MCPOYLE: The Milk Thing
Milk is good for you, assuming you don't have some sort of intolerance or allergy to it. Lord knows Liam certainly didn't have issues with it. Mac and Charlie sure are grossed out by it. In fact, Liam and his siblings seemed to really enjoy a nice, room temperature glass of milk on a hot day.
Given all the other messed up things about Liam, it's kind of odd to suggest that this might be on of the worst things about him but drinking milk like that is just nasty.
RICKETY CRICKET: May Have Sex With Dogs
Do you know the rules for jumping in on a dog orgy? Rickety Cricket sure does, and no one at Paddy's wants to hear about it, especially Charlie. The fact that this is even a joke in the show is taking things a little too far - even for It's Always Sunny.
The idea of being paid to engage in bestiality is disturbing on absolutely every level, and is completely unforgivable - even for a character like Cricket. Hopefully, he's making this one up.
LIAM MCPOYLE: Inbred And Proud
Inbreeding has been a huge part of the McPoyle bloodline for years. When Liam planned to marry Maureen, it caused a huge rift with his brother as he was upset Liam was ruining the purity of that bloodline.
He got over it when Liam explained they were infecting the Ponderosa bloodline, not the other way around. It's heavily implied that Liam has had a long term sexual relationship with both his brother and his sister. It's the only sibling relationship on the show worse than Dennis and Dee.
RICKETY CRICKET: Won't Walk Away From The Gang
Possibly the worst thing about Cricket is that just won't walk away from the Frank and the rest of the Paddy's Pub gang. They all played a part in destroying his life but he keeps going back to them, mainly because they enable his squalor.
Even worse, they encourage it and frequently use him to do the insanely dirty things they want nothing to do with. Until he walks away from Paddy's Pub for good, Cricket's life will never improve.