The evolved form isn't very different, maybe you could rearrange the colouration a bit? Perhaps give it black forearms and feet, to give a tougher boots-and-gloves feel (while still being cute). It's best to not reuse the same palette too, so maybe slightly changing the yellow towards brown or orange could work.
Assuming it's electric-type, perhaps it could do with more electric elements somehow, at least in the adult? (I mean, that I can't tell is an issue, but it's not exactly obvious on Pachirisu for instance.) If it weren't for Elekid I'd suggest plug ears. Maybe some spikes on the ears or head, like a stylised spark? Like this random company logo
. You could echo that on the cheeks to move away from Pikachu too, although at the moment it's like a ground type cousin to Pikachu I guess. Might work on the tip of the tail; like Raichu a bit.
For Ground typing, maybe big stompy brown feet? Again, especially in the evo. Tail could be a drill, or a pneumatic drill, the way it bends looks like it might dart forward like a scorpion pickaxe. Or maybe if you add a central joint it could be like a digger crane. Probably you don't want to go too inorganic though