This took me way too long, haha! Anyways, these are all the Villain!Alex AUs I could come up with + some common ones. If you want to learn more, keep reading.
Trapper!Alex
A pretty common Villain!Alex variant linked to he sitcom AU. I was told about this one on a call. In this AU, Alex still befriends Clyde and stuff, but this time they have different intentions. You see, they actually work for the Lankmann foundation and is therefore luring Clyde into a trap, hence the name Trapper!Alex. They didn't have a proper design though, so I decided to give them one.
Swap!Alex
Another classic! Swap!Alex is part of the Williams Foundation AU by @corrupteddoodles, and it's pretty self-explanatory: Alex is Lankmann basically. I really like this one, it's so cool and one of the only ones on this lineup that is close to canon without relying on the sitcom AU (not saying that's a bad thing, otherwise I'd be a hypocrite). They already had a design, so I just drew them in my style.
Veldigun!Alex
Okay, so this is typically not considered a Villain!Alex, but I'm sorry, the concept of a human befriending a veldigun and becoming one themself is horrifying! I do not think that Alex would be able to mentally handle that, and they would probably already be too far gone if they had befriended Clyde. Tangent aside, I have given Veldigun!Alex a unique name to go along with their new existence: Avery! They are very evil and messed up. (Note to Tammy: no, you can not hug them.)
Cupcakes!Alex
This is a fairly simple concept: MLP Cupcakes, but it's Alex Williams. Out of a weird sense of justice and karma, this Alex decides to kill all the veldigun (and surprisingly succeeds in doing so) as revenge for Clyde being the silly smiling snatcher it is. I don't know how they haven't died yet, but more power to them, I guess.
Proxy!Alex
I was a Creepypasta baby, okay? This is definitely the most edgy one, but basically Alex already had some... problems, but it wasn't anything bad, and they could live without acting on them. But then when Clyde was introduced into their life, it encouraged the dark parts of them, resulting in them starting to kill and eat people. They were chased out of Eastridge and is now hiding in the forest with Clyde. If anyone comes close, they will die, so don't attempt to! (Note to Tammy: no, you cannot fix them.)
Cult!Alex
This might honestly be my favourite one, and I could definitely make something with it. In this AU, Eastridge's citizens reacted differently to Clyde. Instead of seeing it as a horrible monster, they saw it as the true God, coming to punish them for not worshipping it enough. They start a religion - but it's closer to a cult - around Clyde, and every month during the full moon, they sacrifice an unsuspecting traveler or tourist to avoid Clyde returning to steal their children. Alex is a high member of this cult and is often the one to keep the victims in their basement until the day of the sacrifice comes around. They don't get in trouble for this since the majority of Eastridge is part of the cult.
evan is the former director of the student film marble hornets. he was an incredibly unpredictable guy, and known for being a wild card. one day, he cancelled the film and vanished. his former best friend, jeff, tracked him down long enough to convince him to hand over the tapes, and began combing through them, only to start being hunted by evan after he realizes the operator is attached to the tapes. evan is a lot more wild card than alex was in his role, and a lot brasher and more manic.
alex is the best friend of tim, so when tim initially finds the knife and the thing in his attic, alex believes him, although it does take some convincing. he goes along with the whole situation, although he is a lot more cynical than mo, and a good deal more violent against the cult. when tim is kidnapped, he puts all his effort into hunting him down and gets very close to killing brian until they realize he's better as bait.
mo is lee's friend and one of the guys he starts his channel with, but quickly becomes taken over by habit. originally, mo is a very smart allecky guy, but nowhere near as bouncy as evan was in the original role. he's more dry and disinterested.