Humaaans - Mix-&-match illustrations of humans with a design library.
Humanotion - Free avatar pack, perfect for Notion
Control Illustrations - 108 free flat illustrations with customizable characters
Ouch! Illustrations by Icons8 - Professional, perfectly matching, and customizable illustrations for any designs
TinyFaces - Free crowd-sourced avatar gallery including Sketch plugin
Struct Illustrations - Create your own unique story with editable illustrations