Student-style pranks in a world of high fantasy or incredible science fiction technology can be a lot more interesting than in the real world. Just think of some of the "amusing" things that happened to Harry and Ron at Hogwarts.
So when a new character joins an established group, think about ways to have fun with them. Imagine a team of superheroes, who when a new up-and-coming superpowered human wants to join their Power Justice Squad, subjects the newcomer to a series of super-pranks. Awesome.
GM: You've fallen into a dungeon. Take <roll>... 2 damage.
R2-D2: I thought this whole place was a dungeon.
GM: It's a dungeon within the dungeon.
Han: It's dungeons all the way down!
Jubnuk: Ha ha, very funny guys. Prank ol' Jubnuk again.
Lando: Pssst, Princess. Bib's Wedge.
Lando: Wedge, our shapeshifter pilot. That's him.
Leia: Oh! Nice shift.
Lando: No, he's just in a suit.
Jubnuk: You really got me. Again. Guys.
Ortugg: Ha ha ha ha <snort>!
Jubnuk: Oh! Wow, you're really going the whole hog—