Each monster race has a signature class that human characters can also play as. These monsters are hated by humans, but they still seek to slay liches in the dungeons! Monsters can either be played as their signature class, or they can be played as any of the stock classes in Barony! Once you finish the game as a monster, you unlock its signature class for play as any race.
You can also just wear the monster skin as a costume without any gameplay changes if you prefer, and don't worry, you can still play with anyone who doesn't own the DLC.

The Skeleton requires a patient approach, which works since you don't get hungry!

The Conjurer starts with a new spell, allowing them to summon helpful allies who increase in power throughout the adventure.

The Succubus hates blessings and loves curses! She'll also start with some demonic powers.

The Mesmer has a staff, and eventually can learn a spell, which allows her to enlist the service of foes to protect her. Use your wiles to survive!

The Vampire can't eat normal food and must feed on blood instead! Vampires also start with vampiric powers!

Accursed adventurers have a voracious hunger, but also have increased speed and the ability to turn invisible. The Accursed must move quickly to survive.

The Goatman eats tin cans with no need for a tin opener, and can sniff out extra potions from fountains, which is great since they gain some unique buffs from certain brews!

The Brewer starts with a handy-dandy backpack which increases their inventory space. They also have an Alembic which allows them to brew powerful potions!