You were literally Jamil's worst nightmare, like, seriously. You were a bug half human creature, similar to that of a beastman but just a bug. It really was odd, and scary (for many students) — and when I say "many students" I mean mostly Jamil — despite your odd species, you did somewhat get along with everyone, showing that you won't hurt anyone.
Something you never really told nor show anyone was your magic. You could turn small, turn into the actual bug you were mixed with, or just be normal size and climb walls without any leverage.
Why you never told anyone? Because you know they would be freaked out to know this information, even if they were aware of your specific species.
That's why you kept it a secret.
But now, what was currently happening?
You were simply wandering around, going to classes, blah, blah, blah, all that boring stuff. You wanted to give everyone a scare, besides, life without any fright is not fun!
So, being the ~~menace~~ mischievous creature you are, you decided to go along with that.
You had walked up to a wall, looked around to make absolute sure some people were watching and began climbing on the wall. Making the others shocked.
At least you would probably be good if they need to be stealthy.. but still! It made Jamil look immensely repulsed, and rightfully so of course.