It's very simple. "Authoritarian Communists"

Tankie is a pejorative label generally applied to authoritarian communists, especially those who support acts of repression by such regimes or their allies.

The term "tankie" was originally used by dissident Marxist–Leninists to describe members of the Communist Party of Great Britain (CPGB) who followed the party line of the Communist Party of the Soviet Union (CPSU). Specifically, it was used to distinguish party members who spoke out in defense of the Soviet use of tanks to crush the Hungarian Revolution of 1956 and the 1968 Prague Spring uprising, or who more broadly adhered to pro-Soviet positions.

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

Like the other guy said, authoritarian communists.

Or authoritarian communists pretending not to be. The type of people to come out and defend everything China and Russia do while decrying "the west" at every opportunity. Constantly at it with "what aboutisms" and other bad faith arguments. People who claim we should vote third party/not vote while pretending they want to make the US better through these actions, when really they just want the US to fail. Jackson Hinkle types or Infra Haz types.

If I recall correctly, tankies are named because tanks were used to put down protests in Czechoslovakia under the USSR and tankies will defend it.