Res

Katriona is played by Becca De La Rosa. She is a minor character in Mabel.

Season Seven
Res' only canonical appearance is in Episode Forty-Seven: What Happened in the '20s. She breaks into the Martin House with her friend Kat and explores the place, finding a strange painting that her and Kat study. After Kat yells "the door is going to open!", she and Kat are presumably pulled into the Underhill, after Res screams that she "takes it back".

Trivia

 * Res' name means "red-headed."
 * When she swears she's telling the truth, she swears on an unknown person called Val.
 * She is an anxious person who has somehow befriended the walking personification of "no thoughts, head empty".