You know what my concrit entails, Angenesis, so I'll just look at the first one, if you don't mind. xD;
The sprite is, on first glance, a fairly competent example of a difficult splice. You haven't added too much to the base Skitty sprite, but in your defence there aren't too many defining features on Wailord other than its sheer hugeness. However, the tail that you've added isn't exactly perfect. If you try to imagine the splice in your mind, rotating it as you go, you'd see that the tail was off-centre. Because of the way you've shaded the joint it looks like it's attached to the Skitty's side, like a side exhaust on a car. To show the correct way, look at Skitty's stock DPPt sprite:
The tail doesn't directly join to the part of the body we can see. Instead it goes behind it, and we see the outline of the side of the body. This makes it look like the tail is positioned at the centre of the body. Try to bear that in mind in the future.
The recolour is competent, and I do like the addition of the grooves that run down Wailord's underbelly. I also think you've reshaded the tail well, though it could have benefited from just a few pixels of a darker blue at the very base. After all, the light source is coming from top left-centre. I've also noticed that the outline on the tail is grey at times, and it's fairly noticeable. It makes the outline look choppy when zoomed out. The shading on the face bugs me a little; it looks a little bland and flat. This was broken up by Skitty's yellow face on the stock sprite, but this is not the case on the splice. I also think that the lightest shade of blue could have been made a little darker, as it sticks out a little. I think I would have preferred for the inside of the ears to be recoloured, but that's the spriter's choice, really.
Finally, I think the eyes are a bit of a cop-out. =/ I can understand that you were going for a little humour, but I would have preferred to see Skitty's original eyes recoloured and replaced into the sprite. Overall, however, a competent splice, with just a few minor errors that one might take for granted and miss.