I countered this with a Face Hunter deck with a decent curve. Mulligan into as smooth an early mana curve as you can. Your hero power is a nice mana dump if you need it. Calculate each turn how you will spend your mana, even if means playing a card before you are really ready to. 5 damage over and over will put a hurting on you. I really wanted another Timber Wolf but I couldn't figure out where to put it.
He's got some Molten Giants so hopefully you have some good removal up. My deck isn't heavy on removals.
The trick to Living Bomb is you have to kill that minion that turn before it can go off. You can run him into one of Baron's minions. If he dies that way, the bomb won't go off.
Hunter's Mark x2
Arcane Shot x2
Explosive Trap x2
Animal Companion x2
Kill Command x2
Unleash the Hounds x2
Starving Buzzard x2
Tundra Rhino x2
I grabbed the screenshot a millisecond too soon.
If the damage to Geddon hadn't been fatal, I would have run the hyena into the Imp Gang to kill him and prevent the bomb from going off. I wouldn't have played the Houndmaster because I would need it next turn and have to hope for another 4 mana card.