Hunted Dragon Ivory Mask

[kadim]

What happens if I play a Hunted Dragon when other player has Ivory Mask?

[Twanos]

The Hunted Dragon will enter play. It's triggered ability will go on the stack but since there is no legal target, the effect will be immediately removed from the stack. End result you get a hunted dragon and your opponent gets nothing.

[kadim]

wont it be countered because of illegal targeting?

[Twanos]

The trigger is effectively countered as it is just removed from the stack but it is just a triggered ability from the creature already on the battlefield. The creature has already resolved in order to hit the battle field for it to trigger. So the trigger failing can't retroactively put the creature from the battlefield back on to the stack and counter it.

So once again, end result you get the dragon and they get nothing.