Patterninja - Create patterns online
Ouch! Illustrations by Icons8 - Professional, perfectly matching, and customizable illustrations for any designs
Doodad.dev's Pattern Generator - A free tool for creating unique, royalty-free, repeatable patterns.
Control Illustrations - 108 free flat illustrations with customizable characters
Pattern Monster - Pattern Monster is a pattern maker app to create vector patterns for your projects
Humaaans - Mix-&-match illustrations of humans with a design library.