Which design technique do Octocat and Snoo belong to?

Github's Octocat, a little less Reddit's Snoo and some others represent their website accros several situations with multiple designs.

Is there a particular name to this form of design? It looks like a flat design but there must probably be a more specific name to this technique.

I'm interested in this kind of art work but I have no idea how those are made. How do they keep the proportions just right and still manage to change their "mascot"'s position as well as disguise them?

Great design resource

100 Things Every Designer Needs to Know About People (Voices That Matter) Submitted December 06, 2017 at 10:02PM by Cifrado http://ift.tt/2BJzVN7