The Book of Tandros Kreel

[Acinonyx]

Ok, I need help. Last night we were playing the DnD heroes vs. an undead horde. Three of my zombies end their move adjacent to the cleric, who is adjacent to Tandros. One of the zombies is adjacent to Tandros. All the zombies are on the same level, and eligible for the special attack.

Does the zombie special attack Tandros even though he is only adjacent to one of the zombies? Is the zombie special attack disallowed somehow because the one next to Tandros can't participate? Or do they get to roll six attacks in revenge on the mean cleric?