Authoritarian communists, especially those not native to such a state.

Currently it’s mainly the folks who believe China in particular can do no wrong. Historically it refers to supporters of the USSR in Britain

Specifically, it was used to distinguish [CPGB] party members who spoke out in defense of the Soviet use of tanks to suppress the Hungarian Revolution of 1956and the 1968 Prague Spring, or who more broadly adhered to pro-Soviet positions.

More recently it’s applied online especially to people who are knee-jerk anti-capitalist or anti-US, “if the US/‘west’/capitalism is wrong then anyone who opposes them must be right”

More generally, a tankie is someone who tends to support “militant opposition to capitalism”, and a more modern online variation, which means “something like ‘a self-proclaimed communist who indulges in conspiracy theories and whose rhetoric is largely performative.’”

https://en.m.wikipedia.org/wiki/Tankie

Asshole (but left wing)

Its just another meaningless pejorative term usually used at leftists.