Two days later-- Somewhere on the surface of the Poison Rock planet--
"...Nothing here." Robin opened his eyes and sighed, then cut through the space in front of him and jumped, "One spot left."
When he emerged from the other side, he was standing above a swamp that exuded a poisonous scent and all the malicious creatures were moving in it while making the slightest noise possible. One of those creatures was a frog with a skin hat, its skin melting after a dip in the swamp and then growing new skin, and so on~ It was an entire ecosystem that relied on toxins!
But Robin up there didn't pay attention to that complex ecosystem, instead, he closed his eyes for a few seconds and the space around him began to gently ripple, then he slowly opened his eyes and sighed, "Nothing here either, good."