Thanos's preacher, who does the talking and moves everything in the room without touching it.
Ebony Maw is an adopted son of Thanos and a member of the Black Order. Tom Vaughan-Lawlor voices and motion captures him, and the performance is the reason he is the one people remember: he speaks about Thanos the way a convert speaks, not the way a soldier does.
Minor spoiler
Tony Stark and Peter Parker defeat him aboard his own ship and blow him out of an airlock into space. A past version of him, brought forward from 2014, is disintegrated with the rest of Thanos’s forces when Stark uses the Gauntlet in Endgame.