Unlock Models following the list below, then view them in the Entertainment Center:

Emma: Save her
Joshua: Save him
Le Roi: Save him
Devin: Beat him
The Werewolf: Beat him
The Machine: Beat him
The Witch: Beat her
Nephrack: Beat him
Carpenter: Beat the game on Nightmare
Rot Hand: Kill 25 Rot Hands
Rot: Kill 199 Rots
Prison Guard Rot: Kill 20 Prison Guard Rots
Flamethrower Rot: Kill 8 Flamethrower Rots
Gargoyle: Kill 10 Gargoyles
Hanged Spirit: Kill 7 Hanged Spirits
Mourner: Kill 40 Mourners
Aileron: Kill 75 Ailerons
Cultist: Kill 20 Cultists
War Ghoul: Kill 2 War Ghouls
Machine Monster: Kill 20 Machine Monsters
Samantha: Unlock 8 models
Father Esteban: Unlock 12 models
Kassandra: Unlock 18 models