The outline on the belly of the gulpin is a bit too light and not very curved. try using the curve tool?
on the second one, the shading is rather blocky on the ears, and there is a bit too much light shading methinks.
the leafeon edit, is just a leafeon with added vines, so i cant really comment
Well both of your fusions look C+P you should use a bit of scratching to get them looking better
Your leafeon edit: One of the vines is coming out the ground, wether its supposed to come out the ground or out of him i dont know, but it doesnt look right.
And the last one is just pointless but funny