u/relatable_dude

I'm trying to make snow golems deal damage. I've tried /execute as u/e[type=snowball] at u/s run effect give u/e[distance=..1] minecraft:instant_damage 01 and other variations that didn't work anyways. Additionally, this doesn't address the fact that undead mobs are healed by instant damage. Is there a way to even do this in vanilla minecraft?