Here is the full list of all 23 Just a Cleric achievements.
Kill an endangered cardinal, but not in real life.
Get a squirrel to swap out an item on the town's tree stump
Die, and get it out of the way.
Meet Booger Myers and his piggy wagon.
Upgrade any piece of gear to +4.
Bless any piece of gear at the church to +5.
Fail any mission where possible.
Beat the game.
Beat NG+
Reach level 13 to fill your prayer book.
Amass $1000. Wee Hoo!
Play guitar with the Booger Myers Band.
Buy a wand from the enterprising wizard.
Sell something to the shop and free up a spot in your backpack.
Buy something worth $300 or more.
Kill a Giant Catfish.
Kill the demon super boss!!
Pick up a gold-level piece of gear.
Build your total stats to 50 or more!
Kill the cult leader with any dagger.
Kill the albino bat with your bare fists.
Kill the black widow with any bow or crossbow.
Beat the game in Hardcore mode. Yikes!