Ad hominem troll
Ad hominem troll at its simplest, will attack people personally,
rather than the merits of their statements or methodologies.
The ad hominem troll often has already lost a rational argument
about a topic, and thus its goal is to change the argument from
being about a topic, to being about the people opposed to the
troll (which could mean any/all rational person(s) in the
discussion), in the hopes of both discrediting people's ideas
indirectly by discrediting the people, and engendering an
emotional reaction from the people by attacking their egos /
self-image. The "getting a reaction out of" goal is common to
most troll types.