Strategy: The bane of Hearthstone, the high-rolling Big Bad Priest has been haunting both Wild and Standard.  As they say, if you can't beat them, join them... and Big Priest has converted many an unwilling disciple. 

The general strategy is to bring out your huge minions and keep resurrecting them.  Keep board control with your plethora of board wipes and kill spells.  Watch your health, because the #1 way to lose as Big Priest is to get overwhelmed by pressure and face damage. 

Don't try to be too greedy, but be strategic with your board wipes.  Be mindful that your opponent knows you have a million board wipes and will try to bait them out.  Psychic Scream can simultaneously give you breathing room and mess up your opponent's draws (e.g. tossing Silver Hand Recruits into their deck), so use that to your advantage. 

Mulligan: Barnes #1!  Everything else pales in comparison.  Situationally, against Pally you want to keep Spirit Lash, Shadow Word: Horror, or Excavated Evil.  Keep Shadow Word: Pain against aggro decks with a fast start. 

Substitutes: Ysera, Malygos (with Mind Blast), Shadowreaper Anduin, Witchwood Grizzly, Charged Devilsaur