The Giant California Sea Cucumber

The giant California sea cucumber uses its anus as a mouth in spite of already having a mouth. It's very greedy but then when there's food around it's sort of like I'll have a bit of my bum. And scorpions sometimes lose their anuses in you know what some creatures do. Autotomy. So if you threaten them from behind then they drop their tail off but their anus is at the end of their tail. Once they've done that they can no longer defecate or sting indeed.