A lot of these bosses seem to fall to the Divine Spirit/Inner Fire Priest and Garr was no different. Circle of Healing and Mass Dispel are great in this matchup. I had good luck with Mass Dispel on turn 4 into Lightspawn, Power Word: Shield. Then I followed it up with some Divine Spirit shenanigans. If you’re able to either Dispel or Circle the initial wave and get a big minion going it should go pretty easily. Also, Lil’ Exorcist is an awesome card against a full board of deathrattle minions (just don’t accidentally silence it with Mass Dispel)!