Avataaars - Mix and match avatars with a Sketch library
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.
Sketch Icons - Generate a dynamic icon library in less than 5 minutes
Avataaars Generator - A simple avatar generator