Mountain Obyn is a more offensive Obyn that can also summon Sentinel Bloons.[1] He has three abilities:
Sentinel Bloon: Creates a Sentinel Bloon, a Bloon with the Must Pop property, and deals damage to the opponent's Hero when popped but does no damage if leaked.[2]
Brambles: Damages all enemy Bloons that still survive at the end of the opponent's turn.[2]
Dire Wolf: Adds a Dire Wolf, which deals splash damage, to the player's hand.[2]