A long time ago, I had a dwarf frog in the same tank as a sorority of females. One night, after all the lights were off (they waited for the cover of darkness! LOL) my females ate a leg of that poor frog. They'll eat anything and everything.
Now, he might have gotten injured and they just wouldnt leave him alone (probably what happened) but I think the story is better when I say they ate his leg off of him. I turned the light on that morning and found him struggling under six bettas tearing pieces off the stump of a leg he had left. He managed to live years after being a tripod though.