Denise (credited as Linda Gillin)
"Linda Gillen, cast in a previous episode of the mentally challenged daughter of Shirley's landlady, is here seen
in a radically different role." ~
Hal Erickson, Rovi (Girl in Big Black Wig)
Boy, he is not kidding.  I searched through the whole episode looking for her as a charming blonde or brunette.  
On the third viewing I finally recognized her unique profile and did a double take.  This is a nice change of pace
for her and shows the range of Linda's ability:  from a sweet, naive menu entry in "Terror House" to a
gum-chewing bimbo with a "New Yawker" accent.  Very nice.