possible croakamancer powers:
Dead arm - Disables a unit from attacking but not defending (better yet, the arm attacks the owner and must be cut off and replaced by a chainsaw
DeadAIM - allows long distance communication through undead/decrypted units.
Dead as the Dodo - possibly require a linkup but croaks all units of a particular non-humanoid race in a hex.
Dead badger - poison gass trap set by croakamancer. (extra bad when a crap goelm is involved)
Dead beat - prevent/disable leadership bonuses from a warlord.
Dead Man Walking - Random chance of the affected unit dying at the beginning of any turn.
Dead Possum - Fake death - possibly require link with foolamancer possibly something they can only pull on themselves.
Dead Silence - Complete lack of noise in a hex,
Kill or be killed - Kill a friendly unit to prevent your own death or simply heal yourself.
Death Wish - Units attack stats are increased but defense weakened or they die at the end of turn.