The top sketch above is a preliminary piece, obviously. I'm not positive who it's by, but my guess (and hope) is that it was drawn by Dick Huemer, and I suspect it dates from 1931 and was prepared in conjunction with The Little Pest, the second Scrappy cartoon. That short doesn't contain this precise scene, but it does involve Oopy irritating Scrappy and Yippy as they attempt to go fishing.
The bottom drawing is from a 1937 Scrappy coloring book. But it was almost certainly an old publicity piece. In the cartoons of 1937, Scrappy had evolved into a less idiosyncratically-proportioned, vaguely more realistic little boy, but Scrappy merchandise rarely bothered to precisely reflect what the character looked like in the cartoons.
I wish I knew more about the precise details of both pieces — but it's still nice to have both of them, and I'll bet this is the first time they've ever been published in one place.