I've messaged Fencer with a suggestion of a simple variant for Tablut, the idea comes from the film Night of the Living Dead. (I must admit, it is not of my own originality but from http://www.twilightcreationsinc.com/zombies/tablut.php )

The throne represents the basement of the farmhouse, which has been surrounded by zombies. Whites represent the surviving humans, the king represents the lead character in the film.

The game plays as regular Tablut, with the exception that when black (zombies) captures a piece, a dice roll will decide whether that piece will remain on the board but as a new black piece! You could also have an automatic change of colour, but I think the dice roll would add a slight twist without the balance tipping towards black too much.