Shamblers are units of the Lotus Clan, only available in Winter of the Wolf.
About
Much like the Zombies created by the Necromancer, the Shamblers are bloodthirsty corpses brought back to life with necromantic energies by the Lotus Reapers, and every second of their life is a struggle for survival... for the Shamblers (so named due to their shambling gait) need to continually consume the flesh of the dead to avoid a second death.
A shambler's existence is woefully short, brutal and violent. But considering their penchant for attacking and devouring the living, perhaps that is for the best.