when i use in chat /tag @e[type=minecraft:zombie,distance=..1] add tagged
creeper was tagged..
i think /execute as @e[type=snowball] at @s there must be a mistake (for me looks good ) dont know why
I forgot to tell you to adjust the distance if it doesn't work, I set it to distance=..1.5 and it works now. Also, if you want to tag a zombie instead of a creeper, you have to write another set of commands just like the ones I shoed but with the zombie in the selector.