Mijae Djinn

Whenever this creature attacks, flip a coin. If you lose the flip, remove this creature from combat and tap it.

Masters Edition IV

Whenever Mijae Djinn attacks, flip a coin. If you lose the flip, remove Mijae Djinn from combat and tap it.

Summer Magic / Edgar

Revised Edition

If you choose to attack with Mijae Djinn, flip a coin immediately after attack is announced; opponent calls heads or tails while coin is in the air. If the flip ends up in opponent's favor, Mijae Djinn is tapped but does not attack.

Foreign Black Border

Arabian Nights

Any abilities which have already resolved before the coin flip are not undone. Any abilities that trigger when it attacks which have not already resolved will still resolve.

If the Djinn attacks, but you lose the coin toss, then it is still considered to have attacked, and any other abilities that trigger on it attacking will resolve normally.

The coin flip is done as a triggered ability on declaring the Djinn as an attacker.