Humaaans - Mix-&-match illustrations of humans with a design library.
Avatar SDK - AI-powered 3D avatars from one photo
Avataaars Generator - A simple avatar generator
Boring Avatars - JavaScript library to generates SVG avatars based on text.
AVATARZ - Lovely library of diverse 3D avatars
100 Free Userpics - Collection of a hundred free userpics especially for your design projects.