Don't you just hate it when you're a micro who wanted to get close to a macro's maw, but when they breathe in, the suction is so much you start to get inhaled into it?
That's exactly what is happening here, with this micro being pulled in by Leon's open maw as he was asleep for the night. Unbeknownst to him, that micro might end up in his stomach of holding amongst all the treasure. We'll see how it goes...