Zombie Hoards typically evolve over years, lone zombies wondering will gather together in Dens in caves, old tunnels or buildings, piling on top of each other and waiting for something alive to come around. Most zombie dens build up over decades in places filled with undead energy and occur frequently in the under-dark.

Den. As a zombie hoard is a swarm, it may occupy the space of other creatures, swarms or hoards. The space within a hoard is Difficult Terrain and up to four hoards may occupy the same location by piling on top of each other.

Runner. Spawn 1D4 zombies from the hoard anywhere within it's space. These zombie enter turn order immediately after the swam that spawned it. If you use this action the hoard loses 20hp per zombie spawned in this manner.

Grapple. When a creature begins it's movement or enters the Zombie hoard on it's movement the hoard may attempt to Grapple the target with all normal checks. If the Grapple fails the target is not restrained.

Scatter. When a zombie hoard's hit points are reduced to 30hp, the swarm is destroyed, creating three zombies.

Replenish hoard. When the Hoard's health is below 50hp, the Hoard may summon Any individual zombies to join the hoard.

Zombies on their turn will use their whole movement to enter the swarming. On doing so these zombies leave the field, with their remaining health being added to the health of the hoard. Max of 20 zombies.