Skull by Anita F. Barbour

Folded from a square of double-sided Unryu paper

Skull by Anna Kastlunger

Diagrams in BOS Convention 2010
Diagrams in Centerfold Origami Convention 2010
Diagrams in Christmas Origami Book 2009
Folded from a square of double-sided Unryu paper

Skull by Francisco Javier Caboblanco

Diagrams in Orison 19/05
Diagrams in Pajarita Extra 2003 - Fancisco Javier Caboblanco by Francisco Javier Caboblanco
Folded from 2 squares of double-sided Unryu

Skull by Herman van Goubergen

Diagrams in BOS Convention 1998 Autumn
Diagrams in Das Diagramm 38
Diagrams in Le Pli 72
Diagrams in Origami Deutschland 1998
Diagrams in Origami Tanteidan Magazine 72
Diagrams in Origami USA Convention 1999
Diagrams in Pajarita Magazine 75
Diagrams in Quadrato Magico Magazine 53
Diagrams in The Elegance of Origami by Makoto Yamaguchi
Wet-folded from a square of Elephant-Hide and placed on a mirror

Skull 2 by Hojyo Takashi

Diagrams in Fun Origami World by Makoto Yamaguchi
Diagrams in ORU Magazine 16
Folded from a square of origami paper

Skull by Hojyo Takashi

Diagrams in Tanteidan 16th convention
Folded from a square of Tant paper

Skull by Kunihiko Kasahara

Diagrams in Joy of Origami by Kunihiko Kasahara
Diagrams in New Discoveries in Origami 1 by Kunihiko Kasahara
Folded from a square of mulberry paper

Skull by Matthew Gardiner

Diagrams in Day of the Dead Origami by Matthew Gardiner and Steven Casey
Folded from a square of Duo Thai paper

Skull by Mike Jittlov

Folded from a US dollar bill

Skull by Quentin Trollip

Diagrams in Origami Sequence by Quentin Trollip
Folded from a square of double-sided Unryu paper