Not bad for a first animation, certainly a hell of a lot better than mine was haha. The joke wasn't really delivered all that well, the pacing was a bit too slow. The movements were too choppy, I'd suggest adding more inbetweens, also try to add easing, and more bounce effects to make fast movements look a lot better. Also for the faster movements, squash and stretch can really make it look more powerful. That's about it, I can't really judge the art, as I'm not really good enough at art to make a good judge of it.