This is Patches the Pirate HS Legendary Card from the upcoming expansion Mean Streets of Gadgetzan.
It’s a neutral card and reads: Charge. After you play a Pirate, summon this minion from your deck.
Checking in after the release of the expansion this card is bonkers. Pirates received some really strong cards, Pirate Warrior and Pirate Rogue decks are flooding the ladder, and seeing Patches shoot out of a cannon onto the board on turn one is common place.