https://www.ravelry.com/patterns/library/skull-socks-of-fury
Ravelry: Skull Socks of Fury pattern by Adrian Bizilia
Pattern is no longer available.
https://www.zazzle.com/black_and_white_skull_silhouette_pattern_halloween_socks-256204574541837109
Black And White Skull Silhouette Pattern Halloween Socks | Zazzle