Well, a Christmas surprise for the new baby in a cartoon could be a big decorated Christmas tree suddenly appearing in the baby's room. It would be colorful and exciting. Another idea could be a bunch of colorful balloons floating down with tiny presents tied to them.
Often in cartoons, thunder could be associated with some kind of magical or natural force that leads to cuts or disruptions. It could be part of a fantasy storyline or a symbol of chaos.
The cartoon space kid often has adventures such as traveling through wormholes to unknown dimensions, solving puzzles on distant moons, and teaming up with robots to protect space stations.
A good place to look for such clipart is in graphic design forums or communities. Sometimes, users share their own creations or point to useful resources. Another option could be specialized clipart libraries that you might have to pay for, but they usually offer high-quality and unique designs.