2. Chosen for the excessive girth and danger of a hippopatamus.
3. A person that exudes an abnormally high level of the willies to any and all persons within the scope of there powers.
4. A person who is exponentially more sketchy than all references of sketchiness to the user before that point. Hence, the pinacle of a person's dealings with the noun that is sketchy
person 2: ... so whatever did you do ol' chap?
person 1: Well not any nose candy. The young mexicano gentelman you suggested the other week ended up being a real sketchopotamus and I got such a bad case of the willies I almost shat myself.
person 2: Ahhh, do tell.
person 1: Yes, yes
2) A not-so-subtle way of alluding to someone's sketchiness.
George - Yeah man, he's been doing that for like an hour. What a f***ing sketchopotamus.
2) Billy- I'm not so sure I trust that Frank guy you've been hanging around with, Lisa.
Lisa- What do you mean? He's a total sweetheart. Just yesterday, I ran into him at the supermarket and then AGAIN at the dry cleaner.
Billy- Let me just put it this way: if Frank had a favorite animal, it would be a sketchopotamus.
It can also be used as a prime example of Dane Cook's humor (however this is no Dane Cook joke, its just like one!). Basically, take a word, attach another and then brand it.
Guy 2: "Shit dude!"
Guy 1: "Yeah it was totally sketchopotamus".
Alternatively, Guy 1 could have said he was feeling "sketchopotamus".