I know everyone is going to say this, but I’d say Sully could be the scariest. Ricky is my favourite though!
Ricky’s great! Those are some great teeth he’s got. My favorite is Harley P. Gerson based on his unusual looks.
But scariest? Based purely upon appearance, it’s a toss up between Pete “Claws” Ward and Henry J. Waternoose. Waternoose’s crab legs and claw-like hands are really creepy. Pete “Claws” Ward has got sharp teeth as well as those long Woverine claws!
On a sidenote - Bile WAS scary for about three seconds at the beginning of Monsters Inc. Then it turned into one of the funniest scenes I’ve ever watched! 
I’m going to be honest, I don’t think any of these monsters would have scared me as a kid…somehow, these monsters don’t seem to come off as scary monsters for me…if anything were to scare me as a kid, it would be a horror movie version of a monster but these? I’m sorry but I would have to say no…
None of the monsters in this movie would have scared me as a kid, except maybe Fungus. If he TRIED to act scary, I’d have laughed my skinny little butt off, but if he’d have started solving complex math problems out loud, using words like “cosign” and “pi”, THAT would have been very stressful for me, to say the least. I am SO not a math geek, and people who are have always seemed a bit “scary” to me, lol.
Now, if a Ringling Bros. CLOWN had walked into my room in the middle of the night, I would have totally freaked out! Monsters, no-I would have been absolutely thrilled for anything scaly and reptilian to show up, since even as a very young child I was already obsessed with dinosaurs, snakes, alligators and other reptiles or reptile-like things, but I was absolutely terrified of clowns.
pitbulllady
Yeah, I have to agree with what a few others have said- the monsters aren’t really that scary, funnily enough. 
Bile at the beginning, before he made all of those silly mistakes, was pretty scary though, with his glowing eyes and creeping presence. Sulley might be scary in a sort of shocking way, if he just storms into the room roaring, but his appearance is just too cuddly to be scary just to look at.
Definitely Ted. Given that I have often wondered why a gigantic dinosaur-like monster would arbitrarily cluck like a chicken, my imagination has run wild with ideas about what he looks like. Plus, I am immensely afraid of things larger than myself.
Waternoose. I hate spiders. (except Tarantulas) Freaks me out and I just wanna squish him.
So I’m guessing you weren’t a big fan of Rosie from A Bug’s Life either?
Oddly enough, probably Mike! I still have this bizarre memory of this dream I had when I was 6 or so, of being out in my neighborhood on Halloween with some other kids, and this scary one-eyed monster being up in a tree and looking down at us. I couldn’t tell you now exactly what it looked like, but I remember it as being in the vague general “Mike” ballpark (and this was long before MI).
Yeah, but Waternoose didn’t look like a spider. He was more like a crab, definitely crustacean in appearance. He’d probably have a pretty rough time around Chesapeake Bay!
pitbulllady
Of course that’s not to say Henry can’t “spin webs” himself chuckles
Pixar Builder: No, I love Rosie. ABL is my favorite Pixar film.
pitbulllady: I know he is more like a crab, but when he scuttled like that along the carpet after Shag Rug, I got the … heebie-jeebies. xD He is just scary when he is mad. And crazy fast for an old guy. shudders
Despite being over 120 years old…Waternoose is no old man in terms of how he moves. He’s surprising in many ways.
I think any monster might have scared me… or if Monsters Inc had been made when I was that young I might have the opposite reaction and go “Wow, Mike and Sulley are in my room!”. 
Lol, that’s actually pretty funny…speaking of monsters, anyone notice how when the movie first starts the red eyes under the bed totally reminds me of TNBC’s monsters under the bed “with teeth razor sharp and eyes glowing red!”
Haha, I always thought that too, Princess_Darkness, though if any of the creatures from Hallowe’en Town turned up in my bedroom, I’d be much more scared than if anyone from Monsters, Inc. popped up.
Yep, gotta agree with you on that one lizardgirl, for certain if any of those monsters showed up in my bedroom, they would probably scare me…except for maybe Jack and Sally but everyone else, totally scary…
I think the monster that would’ve scared me the most is the monster with the tentacles and the big puffy hair on top. According to Pixarpedia, his name is Bud.
Great topic.
I think Waternoose would have scared me a lot. I remember some horror movie with crab creatures that bothered me a lot after I had watched it.
Agreed, Waternoose is the creepiest