kaaramel:

extremely dumb concept: xenocarcinisation. we discover independently evolved life on an alien planet and most of their lifeforms are bizarre and mostly unfamiliar but there’s one or two ocean-dwelling species that look like pretty good facsimiles of regular ol’ earth crabs. every time. every time we find some uniquely developed source of multicellular life we keep findin crabs. they’re just such a good shape to evolve into. imagine crabs scattered across the universe.