Minifigure, Head, Modified Snake, Cobra with Open Mouth with Molded Trans-Orange Eyes and Flames Pattern : Part 41201pb01 | BrickLink
Lego Ninjago Minifigure, Head, Modified Snake with White and Black Scales | eBay
Lego New Reddish Brown Minifigure Head Modified Snake Cobra with Closed Mouth | eBay
Minifigure, Head, Modified Snake with 4 Yellow Eyes and Lime Scales Pattern (Spitta) : Part 98150pb01 | BrickLink
LEGO part 98143pb02 - Dark Blue Minifig, Head Modified Snake with Fangs, Red Eyes and Yellow and Dark Bluish Gray Scales Pattern (Slithraa) at BrickScout
Old Elementary: Midgard Serpent Head | New Elementary: LEGO® parts, sets and techniques