I understood and got the joke you were trying to convey with this short animation - I just didn't think it was funny. The idea and the joke itself is funny and just don't think the delivery was very well done.
The animation could really use some practice and work (but a decent enough start). The punchline didn't really exist and continued with the animation of the work involved with taking care of that many pokemon and then him trying to get rid of them/some. It felt more like two jokes without good comedy timing.
I'd also comment that the sound needs to be better and for the effect of the joke I think having the Professor easier to understand and go into more detail (instead of two examples and then blah blah blah blah).
Great idea though and not a bad start! Keep at it!