Menace Pack tactics — Whenever Minion of the Mighty attacks, if you attacked with creatures with total power 6 or greater this combat, you may put a Dragon creature card from your hand onto the battlefield tapped and attacking.
A Dragon creature card is a creature card with the creature type Dragon, not necessarily a creature card with the word "Dragon" in its name.
You choose which player or planeswalker the Dragon is attacking as you put it onto the battlefield. It doesn't have to be the same player or planeswalker Minion of the Mighty is attacking.
The creature card is already tapped and attacking as it's put onto the battlefield. Any abilities that trigger whenever a creature becomes tapped or whenever a creature attacks won't trigger.