Avataaars Generator - A simple avatar generator
Avatar Picker - User friendly, in-page avatar changes for your web app
Humaaans - Mix-&-match illustrations of humans with a design library.
100 Free Userpics - Collection of a hundred free userpics especially for your design projects.
Personas by Draftbit - A playful avatar generator for the modern age.
Bottts - Mix & match robots with a Sketch library