I traveled for perhaps half an hour then, leaving the place far behind me, before I halted and took my breakfast in a hot, bleak valley smelling faintly of sulfur. As I was finishing, I heard a crashing noise. A horned and tusked purple thing went racing along the ridge to my right pursued by a hairless orange-skinned creature with long claws and a forked tail. Both were wailing in different keys. I nodded. It was just one damned thing after another.
Also in that book, the encounter with the Sphinx. It very politely waits for Merlin to wake up and recover so it can ask its riddle and eat him... leading to a debate between it and Merlin on the fairness of the riddles for which the Sphinx is clearly not prepared. It ends when Merlin poses a riddle of his own (What's red and green and goes round and round and round?) and stumps the Sphinx. You almost feel sorry for the poor thing.
And as funny is the call back in Blood of Amber. Merlin is confronted with another guardian creature, a sorcerer-eating devil guarding a hallway. Merlin asks if it's going to ask a riddle, and it says it doesn't usually, but just for the hell of it, "What's red and green and goes round and round?" Merlin chimes, "Oh, you know the Sphinx." The Demon just goes, "Shit, you've heard it before," and is a little put out. Then it boasts that only a Lord of Chaos could get past it. When it finds out that's exactly what Merlin is, its last word is a simple, "Shit."
Random chooses how best to start his tale in The Sign of the Unicorn. Finally, he begins:
While sex heads a great number of lists, we all have other things we like to do in between...
Once when going down to visit the Pattern, Merlin is stopped by a guard who tells him that Gerard says there's a loose step. Merlin asks which one, only to find out that though Gerard will swear on it, nobody else in the castle has noticed any loose steps. Merlin then moves on, and a couple chapters later, while going down the stair, finds one with a note pinned to it, just reading, "This one, damn it!"
Corwin doing the magical equivalent of drunk-dialing Eric with the Trumps, for the sole purpose of flipping him off and hanging up again.
Corwin versus a creature out of the Black Circle in book 2: