This tanky and versatile deck can easily defeat all of the PvE content in the game. Overall, the deck provides good map control and allows you to zerg with Skeletal Mages. Here's a breakdown on each mini and their roles:
Abomination: Tankiest mini in the game, used for pushing in lanes.
Necromancer: Good ranged mini to place behind Abomination and take care of air units.
S.A.F.E. Pilot: Excellent map control and anti-air/crowd.
Whelp Eggs: Good counter and boss killer.
Quilboar: Chest grabber and temporary tank for Harpys.
Harpy: Insane DPS, good for killing bosses, towers, anything tanky. Place Quilboar to take aggro immediately before Harpies get to the target.
Other suggestions: you can easily swap out Abomination and Necromancer for other units, but I find these to be highly effective Undead units (for the Army bonus) in PvE, whether it's heroics or dungeons.