Skull is cynical and straight to the point, most of the time doing the talking and sarcastic remarks for Hex.
In the series premiere, Skull was summoned by Hex to assist her during the Skylander Games, but the trial left both of them exhausted. Because of their performance, Hex and Skull failed the Skylander Games and had to study for another year at Skylander Academy. Skull then ranted to Hex that they lost to Bad Breath, whose only ability was burping.
Skull is based on Hex's skulls in her Series 2 figure artwork and figure, with slightly different coloring.