Iron golem and ravager can attack their targets through walls.

1-build a short room
2-summon an iron golem with commands or a ravager(summon one entity for not letting a fight starts)
3-hit the iron golem or the ravager
4-enter the room
5-stand near any wall inside the room(become contacted to the target wall)
6-iron golem or ravager can attack you through the wall which makes no sense.