I like how they kill other creatures in various ways (and not necessarily eat them). I also like how they die - some explode, some burn up, and a whole lot of other ways :)

I like it when they don't have eyes.

Monsters that are built up of the psyche of people to show their most basic fears manifested as a physical being or creatures that represent one person's mind are always favourites of mine. Sadly the classics for those don't work so well any more thanks to romanticising them. They have to be re-imagined as other things, like whatever those things in Society were. Guh.

Otherwise I like monsters that are meant to be happy, friendly, soft, basically what you'd want in a giant pet if you could.

I like to see in monsters unique behavior, such as having an obvious culture of their own.

I like ones that like belly rubs

I approve!

Inflatable monsters!

I like monsters that are sort of adorably creepy.

Squishy monsters! I love the ones you draw that always seem so soft and pliable, especially if you can just sink right into them~

(Mmmmm buckets of blood and guts.)

I love monsters that are just trying to be the best monster they can be. When they are just trying to fit in.

In terms of physical qualities, something that is eerily human in certain ways, something that has too many teeth, like how a shark has rows behind rows. In terms of presence something that is either extremely well documented in terms of what it has done versus what we still don't know about it, or something that you see out of the corner of your eye a lot, you know it's there but you don't know what is completely looks like, it gives of the feeling of being hunted. These are my favorites for scary monsters.

My favorite things about something else, like kaiju style monsters, is the sheer ambiguity in their actions. I have a lot of favorites in older Godzilla movies, he destroys things because whatever, but at the same time he'll turn around and pulverize another monster for showing its face.

Huge monsterous clawed feet for stomping! T-Rex feet for example

Maybe preds who prefer to play or toy with their victims, like pin them down and lick them and stuff?

I love monsters that are vorish in nature, swallow victims up whole and alive and trap them in their belly. ^^ I also love impressions and bulges on said monster and a grand example of a Monster I remember is definitivaly Terror Toad. ^^ He was one favorite monster, as he did swallow two the rangers up with his mouth. <3

And blobs are a big favorite of mine.. ^^ So made for struggling bulges and impressions. <3

I think its the awe they create that i like. I like Kaijus and they do bring in that air of sheer epicness due to their size and stature ( dammit now I wanna re-draw one I roughed a few years ago! )

I kind like parasitic monsters, the kind that latches onto a victim the uses them as a renwable food source, weithed it be for fluids, energy or emitonal energy. Wjat is even better are the kind that slow transforms theor victims to suit their needs. Like a slime that force ffeds themselves to someone and rhem fattens them up for warmth. Or like maybe a face hugger kind of monster that latches onto someone's head and takes control, alow turning them into a bigger, monsterois and vorsih version of themselves.

Then their are the monster who tend to see people as food, but also as pets and trinkets. Like maybe a monater looking for a mate captures a person only to offer them to a female of their spices. Or the monster takes their victim to their den to keep for company, treating them as they would a dog, feeding them, walking them, maybe putting a collar on them or some mark of onwership. Monsters who have a pouch or some sort of storage are espically perfect for this.

a monster that really scare me are those that could very well exist in our every day lives: human beings with psychotic trains of thoughts.

so a kind of monster that i do like is something that is far from reality. they may attempt to look real but you know it's a guy in a costume in the end. i enjoy the cheese factor in a lot of old (and new) shows, specifically from some power ranger/super sentai and kamen rider shows. in a sense, i do prefer a costume monster over any animated ones.

but specifically looking at the monster itself, i do like any monster in general that does try to overpower you slowly in some way. specifically in no particular order: vore (then digestion), slime, wrapping (with tail, tentacles, or other stuff), physical contact (rubbing, bear-hugging etc).
it helps if the monster is physical.

i do prefer monsters that do not kill or want to have dirty fun time with their victims. that's definitely two traits i don't like in a monster. it links back to the fact that i prefer things far from reality. also, sex and kinks are just not for me if they are done tastelessly. nothing wrong with having a monster have these traits, i just prefer them not to be dominated by said traits.

I like it when the monsters are aliens.

The perfect mix of incredible strength and a gentle, goofy nature

I like when the monsters get caught ^-^ They all seem to have such great expressions.

They've got to be smart. The best predators are the ones that are capable of figuring their prey out, like the Graboids in Tremors or the Velociraptors in Jurassic Park.

I kinda like werewolves and other creatures that can change shape (they don't neccesarilly need to have a human form) and in the case of human ones, I like it when that person has ALWAYS had that power and is used to it, rather than one who ends up with the ability later and is unaccustomed to it. (Actually I kinda like all sorts of "ability" users, mutants etc really).

Also FLUFF

You remember that cartoon "AHHH! REAL MONSTERS?"

Stuff like that.

I like the concept of monsters drawn from nature our own world-- that transform their victims in some way to indirectly help the monster. It's icky when we're talking about a parasite, but could be interesting in a monster. :)

Critters that are made of Goo and/or polymoprphic are neat. :)

Critters with bitey tail mouths are cool. :D

Otherwise, I've always been a fan of monsters as gentle and misunderstood, ever since Anne McCaffrey redifined Dragons as beings of grace in Dragonriders of PERN.

I always love stuff that at first glance is kinda cute and adorable, but changes into a more vicious, truly intimidating, scary side when attacking. A "Omigawd, look at it! " form, then changing into a "OHMYGOD, KILL IT WITH FIRE!!!" form when hungry or threatened.