Locke & Key is one of those series that sweeps up its fans and keeps them obsessed. That goes for both the comics and the Netflix series. One of the biggest fascinations with the series is, of course, the keys.
The keys introduced in both versions of the series have intrigued fans from the start, so that's what we're here to talk about today. While sometimes the keys varied between the two mediums, there's still a lot to learn about their mysterious ways.
Note: this list contains potential spoilers for future Locke & Key episodes, thanks to the inclusion of keys from the comics. Nothing is certain, however, as keys that have already made an appearance have already been altered.
Age Key
The Age Key is essentially exactly what you would expect it to be. It turns the user into an older (elderly) version of themselves. Body first heard about it from Echo, who listed it among several other keys.
Alpha Key
(Spoiler warning) Some keys have a natural counterpart. Where the Omega Key can put a person at risk of being possessed, the Alpha Key will do the opposite. It will lock away (kill) the demon possessing any person.
Angel Key
Don't worry. The Angel Key doesn't involve death – there's another key for that. Instead, the Angel Key provides a beautiful pair of wings. Wings which will actually work, thus granting the user the ability to fly.
Animal Key
The Animal Key is linked to a door, and as you might imagine, going through that door (after using the key) will transform you into an animal. Doing this grants you the additional ability to communicate with critters of the same species. To return to human, you must pass back through the door.
Also noteworthy: the opposite also works. As in, an animal can become human, if they were to walk through the doorway.
Anywhere Key
Fans are likely very well aware of this Key. The Anywhere Key becomes a portal to any other door, provided that it has a door (and that you can clearly picture it in your mind – that is vital). It only works on locations the user has previously been to.
Bitey Key (Grindhouse Key)
The Bitey Key, aka the Grindhouse Key, is another useful key in terms of taking out opponents. Unlike the Mirror Key, it does not intend to trap. The Bitey Key instead will create a massive mouth, which will eat whoever enters.
Chain Key
The Chain Key goes hand and hand with the Great Lock. This Key can neutralize and control the Great Lock.
Echo Key
The Echo Key, when used in the Well House, will bring back an 'echo' of a deceased person. As in, it will (and should) bring back their voice. They cannot leave the Well House.
Enigma Key (Question Key)
The Enigma Key is exactly that: a question, a mystery. We've seen it used in artwork in the graphic novels, but still don't know what it does.
Gender Key
The Gender Key allows a person to swap their gender, becoming the opposite of what they were, provided they go through the Gender Changing Door after unlocking it with the key.
Ghost Key
The Ghost Key works with the Ghost Door. Entering through the Ghost Door will turn you into a ghost. But if the door is shut while you are in that form, you will stay dead.
Giant Key
The Giant Key does exactly what you would expect. It makes the user grow to a much larger size. Additionally, the key itself is giant in scale, being the largest of the set.
Harlequin Key
The Harlequin Key works with the Harlequin Wardrobe. Without the key, the wardrobe is nothing special. But use the key, and you'll find itself previously hidden.
Head Key
The Head Key allows the user to enter somebody's head, including their own. That means they can dive through memories and other secrets within the mind, as well as inserting new ones.
Hell Key
The Hell Key appeared in The Sandman crossover (Hell & Gone), and supposedly the owner of the key also rules over Hell itself.
Hercules Key
The Hercules Key works alongside the Hercules Necklace. If you wear the two together (for the key fits inside the necklace) you will, unsurprisingly, gain Herculean strength.
Identity Key (Skin Key)
The Identity Key, aka the Skin Key, allows the user to change their appearance at will. As long as they can imagine it, they can transform into it.
Keyhouse Key
(Spoiler warning) The Keyhouse Key was created by Tyler Locke in order to recreate the destroyed Keyhouse.
Matchstick Key
The Matchstick Key can and will set anything on fire, so long as it makes contact with the item (or person).
Mending Key
The Mending Key, when used with the Mending Cabinet, can repair any object put inside. There are limitations to the Cabinet, which become clear later in the series.