In general, mobs will not attack or otherwise harm entities on the same scoreboard team as themselves. However, in addition to Endermen attacking their teammates (which has already been reported), there are other exceptions.

Slimes and Magma Cubes will not target players on their team, but will still damage them upon contact.

Withers will not actively pursue entities on their team, nor will they attack with their main head, but their secondary heads will still fire at teamed entities.