"Indeed, I have not." He's not too worried about that, though. If there are several planes of existence (supposedly), is something like different worlds so strange? In fact, do they even count as different, when existence is the same? Besides, on a very mundane level: "The world is a big place."

That's enough of an explanation for him, for now. What matters is that they're here, and they exist. The rest can follow.

Mutated, she says..? He looks at the jellyrabbits, but they're suddenly so far away that he's not sure how they managed to reach those speeds without him noticing. "We have fairies, demons, ghosts, and monsters... among other things. If these are mutated animals as you say, they'd fall in the fairy category - but I've never seen such creatures travel in groups."