19 cards where the illustration contains “three-headed”

Boneyard Aberration (Jumpstart: Historic Horizons #14)
Branching Evolution (The Lost Caverns of Ixalan Commander #234)
Capricopian (Commander 2020 #58)
Daybreak Chimera (Theros Beyond Death #10)
Debt to the Deathless (Dragon's Maze #64)
Elspeth Conquers Death (Theros Beyond Death #13)
Gnostro, Voice of the Crags (Commander Legends #276)
Illuna, Apex of Wishes (Ikoria: Lair of Behemoths #379)
Kunoros, Hound of Athreos (Theros Beyond Death #341)
Ojer Kaslem, Deepest Growth // Temple of Cultivation (The Lost Caverns of Ixalan #204)
Ojer Kaslem, Deepest Growth // Temple of Cultivation (The Lost Caverns of Ixalan #204)
Satyr's Cunning (Theros Beyond Death #152)
Scion of Calamity (The Lost Caverns of Ixalan Commander #93)
Shake the Foundations (Rivals of Ixalan #113)
Sleep of the Dead (Theros Beyond Death #66)
Treeshaker Chimera (Theros Beyond Death #297)
Underworld Cerberus (Theros #208)
Underworld Rage-Hound (Theros Beyond Death #163)
Wildfire Cerberus (Journey into Nyx #116)
Woeleecher (Shadowmoor #27)

It is the moment of discovery, the triumph of the mind, and the end of these results.