Voltron reference
This requires the Goblins vs. Gnomes expansion. Have two mech cards and the Mimiron's Head legendary card on the board. After all three minions are in play, at the start of your next turn V-07-TR-0N will be summoned and replace the three minions. V-07-TR-0N has "Mega Windfury", allowing the minion to attack four times in a single turn. Also, the minion has charge, allowing it to attack as soon as it is . Although it only has four attack and eight health, there are various ways that the attack value can be increased.