Man the only games I played that let you be the monster were games that have been shut XD. There was Evolve a Game where you play as a monster vs 4 hunters. And Alien clonial marines where you can play as the aliens in multiplayer. I found them both enjoyable even though they are known to be bad.

I loved Evolve! Wraith and Gorgon were my favorites, I really wish that the developers had taken a closer approach with the game and had fixed some of its problems. I haven't played Colonial Marines personally, but AvP 2010 was where I originally got my xeno fix, with the different campaigns and being able to play xenos in multiplayer it was really really fun~

How could I forget AvP lol. Avp Was fun and still is since I still have it, though now its very hard to find a multiplayer match. I too Always used wraith and the Kraken, they were my best Monsters, wraith is alluring because she has no face lol.

I did enjoy Alien Colonial Marines though because you could add upgrades and a few moves for your aliens and were able to change parts about them like the head and body color and such. There were also specials like a crusher and a boiler and classes like a spitter, Lurker, and soldier. Aside from that I heard the same studio's that made MMO's Like neverwinter and Star trek online are Making an alien game, probably MMO. Hope it allows us to play aliens tho and not just human Marines

Colonial Marines sounds pretty cool actually! I've been meaning to play it because apparently a lot of the AI problems the xenos had in the campaign were a result of a setting that was flipped in the .ini or something like that. Was a simple thing that improved the game hugely

Yeah the story mode was ehhh. I found the Multiplayer to be the best part of the game really

Not "that" kind of monster, but.. One of my favorites is Medievil. Main character is noble skeleton knight :3

Ahh that's a fun concept! I love undead heroes

The only example I can think of that I remember playing where you're a monster strictly speaking was Natural Selection 2, which I just looked up on Steam and is now dying because of an increasingly toxic community, surprised its still alive at all since its from 2012. (If you're into maws or whatever you're in luck because the camera perspective is inside their mouth looking out.) Dead By Daylight lets you play as slasher flick villains, some of whom are more monstrous looking than others. I guess Skyrim let you be a werewolf or a vampire. Stretching the definition further, I might include Vampire: The Masquerade - Bloodlines, definitely a very solid recommendation there. If you create a Nosferatu clan character, you'll be on the monstrous side. Getting into more big-brain territory, and not just for stretching the definition further, I can recommend Prey (2017) and Soma. Neither have you playing as that much of a monster, at least on the surface/at the beginning, but both deal very heavily with questions of personhood, which someone who's into monsters might appreciate.

I played Natural Selection 2 back when it came out and I had an awful computer, ran the game at 15-20 frames per second but I loved the asymmetric dynamic!

Haven't played Dead By Daylight but I've heard good things~

Haven't heard of The Masquerade, but I have heard of Prey and Soma, I've played some of both but haven't finished them and they're fantastic games! The Typhon(?) in Prey are such an excellent design aesthetically and functionally

Soma is somewhat unfortunately best in the Safe mode they added - the horror gameplay was only hide-and-seek anyways. Nonetheless, the writing still carries the experience easily, and without any danger from enemies the pacing becomes pleasantly brisk, my playthrough probably totaled 6 hours. Prey of course is phenomenal, the art team over at Arkane is truly special, particularly whoever does the effects. VTM is an old-but-gold gem from the early 00s. Popular tags on its Steam store page include "cult classic" and "masterpiece", and its reviews are very-to-overwhelmingly positive, both for good reason.

There's a game on steam I found that I can't remember the name of, but you're literally a flesh monster on a space station that gradually grows stronger. The movement system gave me pretty good trypophobia feelings, but I can't remember what it's called for the life of me...

I think maybe Carrion? I looove that game, actually releases in a few hours here!

That was it! Looks amazing!

Only examples i can remember are Evolve and Natural Selection 2. I played both of those games, had quite a lot of fun, especially Evolve x3
Being a gigantic alien monster is great XD