It's pretty bad. All you did was recolor a mew and slap Slowpoke's head on it.
uhhh. that's what fusing is!
That is only one part of fusing. Your job doesn't end as soon as everything is the same color and connected. That's when you need to get creative and think, "How can I make this look like an official Pokemon sprite?" You could've redrawn Mew's neck and abdomen larger or redrawn the outline of Slowpoke's head smaller. Perfection is never necessary but the body parts do need to fit together well.uhhh. that's what fusing is!