A troll or other miscreant who jumps into an online group or forum, usually to push a view that is contrary to that prevailing in the group. They usually melt away when asked to provide evidence, citing 'bullying'. Often extremely smug and rather stupid.
A parachutist landed in our FB group today to 'educate' us all about how we are wrong about absolutely everything, ever.
by Chowbelanna May 01, 2015