Dark Qiviut

Why was Tommy Pickles beating up a monkey? 

The rapid-fire trifecta of gags beginning around 1:30 absolutely kills me every time: the absurdity of Bubbles' impersonation of Mojo, followed by Mojo's blatant self-contradiction (Roger Jackson's line delivery is hilarious) and finally Buttercup capping off the awkwardness via the fast cut of her punching Mojo in the exact same way as before. And that's not even referencing "no, really, do you think?". It's essentially a quintessential example of the surprisingly slyness of Craig McCracken's comedy: it mines relatively simple conceits for jokes, yet augments them with amusing new angles and hilarious meta dialogue, which generates a uniquely 'charming' aesthetic.