Ouch! Illustrations by Icons8 - Professional, perfectly matching, and customizable illustrations for any designs
Wannathis - 3d illustrations and freebies
Control Illustrations - 108 free flat illustrations with customizable characters
Shapefest - A massive library of 3D shapes for everything!
Humaaans - Mix-&-match illustrations of humans with a design library.
ccclaymoji - A fun little tool to make emojis that have a fun 3D-like effect.