Here is the full list of all 13 Brain Guzzler achievements.
Collect over 50 coins on a level
Destroy 30 Hay Bails
Destroy 20 Hedges
Die by hitting 20 walls
Kill yourself by eating your chain over 10 times
Disarm 50 mines (naturally or using Bomb Proof perk)
Get blown up more than 50 times
Collect over 100 coins on a level
Create an undead conga of more than 50 zombies
Create an undead conga of more than 100 zombies
Create an undead conga of more than 150 zombies
Create an undead conga of more than 200 zombies
Create an undead conga of more than 250 zombies