Skull by Ryo Aoki

Diagrams in NOA Magazine 253
Diagrams in Origami Decorations for Halloween
Folded from a square of double-sided Unryu paper

Skull by Stephane Gigandet

Diagrams in Origami for Halloween by Stephane Gigandet
Folded from a square of origami paper

Skull by Steven Casey

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

Skull by Wayne Brown

Diagrams in BOS Magazine 282
Diagrams in Origami Inspired by Shakespeare
Folded from a rectangle of duouble-sided Unryu

Skull 3 by Hojyo Takashi

Diagrams in Tanteidan 3rd convention
Folded from a square of double-sided Unryu paper

Skull emblem by Hojyo Takashi

Diagrams in Tanteidan 20th convention
Folded from a square of origami paper

Skull ring by Kunihiko Kasahara

Diagrams in Fun Origami for All by Kunihiko Kasahara
Diagrams in New Discoveries in Origami 2 by Kunihiko Kasahara
Diagrams in NOA Magazine 434
Diagrams in Origami Decorations for Halloween
Folded from a square of Poopoo paper

Talking skull by Jeremy Shafer

Diagrams in The Elegance of Origami by Makoto Yamaguchi
Folded from a square of Duo Thai paper