Pichu is a pretty fun and interesting idea, adding a rather different approach to the game as opposed to that of Pikachu. However, there are some things that should be addressed in the next update.
For one, Pichu's model, as OP said, needs some polishing. Despite the fact that Pichu is just as tall as Kirby, he is still, half-the-time, immune to grabs. Even when Kirby crouches, he can still be grabbed, whereas if Pichu crouches or even stands, Grabs tend to go right over him or through him. With grapplers, this presents a rather difficult and broken challenge usually up to the luck of the draw on whether or not the little rat get pummeled or not. In addition, half of the standard attacks like Captain Falcon's jab, will soar right over his head half the time, much like the grabs.
Second, his grab is rather ridiculous. The priority, speed, and almost lack of cool-down on Pichu's grabs almost guarantee him the ability to close down any opponent's approach. His up-throw is on par with that of Ivysaur's up-throw, which makes little sense given how small Pichu is. Granted, it doesn't do much damage, but he shouldn't have the knockback strength on his up-throw as that much.
Third, the amount of time that Thunderjolt lasts is a bit crazy. It has the ability to loop around Final Destination twice, when Pikachu's only goes from one end to the other. I would say reduce the amount of time it lasts so that at most it only goes around one full rotation.
Finally, I'm a bit confused on how his Static is working. Sometimes it will deal extra damage to opponents, sometimes it won't. It's a really cool ability that, if it did damage like I think it is supposed to, would definitely mix up gameplay and force opponents to rework their strategies as opposed to abusing moves with electric-based damage.