Ok an opponent's creature has "{Tap} deal 1 damage to target creature or player"
Can he activate it on my turn as well as his turn? If its untapped can he tap on mine, untap, tap on his?
Yes, so long as it does not have summoning sickness.
RESOLVED
Wow ping is some s***
- Edited by Dudecore
Yes, they can do that. Just adding confirmation. Additionally, keep in mind that unless stated otherwise, abilities may be activated at instant speed (any time you could play an instant).
I did not know that wow
But only when you have priority. For instance, if it's my main phase and there's nothing on the stack then you cannot ping me.