Hank Pym
At one point, Hank Pym grew to a large enough size where he encountered the cosmic entity Eternity, claiming to the former that he is Earth's "Scientist Supreme". When Hank Pym told Loki about this, the trickster god claims he was using Eternity's form in order to trick the so-called Scientist Supreme. Hank Pym disputed Loki's explanation. Whether or not it was indeed Loki-in-disguise has not been answered.