I currently fighting some pretty aggressive fin rot (I think) in Keller, trying to win the battle before it reaches his body, so I'm having to open his tank lid to add meds, etc, and he's used to me opening his lid to either play or feed him, and he just got so frustrated (or attention seeking) that I had his lid open and my arm was sort of laid across the top as I dosed his medication and he leapt at my arm! Full body out of the water. Scared me half to death! I know bettas are jumpers, but Keller's never really been one, so I think it's adorable.
Wish me luck with the fin rot- I will be devastated if I lose him, he's my only fish.