A troll that spends it's time trollbaiting other trolls. Wasting the time of those most intent of wasting the time of others
For instance a Cannibal Troll could post something like this
("Hi. Does anyone know if it's possible to use a background that would essentially turn my computer monitor into a mirror? Scanning a mirror doesn't work") He would do this purposely to attract trolls and feed of there negative comments. For every troll that pays attention to a Cannibal Troll another innocent bystander go's unmolested.