Here is the full list of all 12 Train Bandit achievements.
Unlock E. Lawphant
Unlock Bright Bandit
Kill 2000 enemies
Kill 99 snakes
Shoot 1000 bullets
Die 1000 times
Unlock Box Cat
Unlock Flap
Unlock Doughnut
Unlock every bandit
Kill Poncho quickly
Kill three different sheriffs in a game