Lillian Pendergrast is resident of Elk Grove and minor character seen in the second season of Ash vs. Evil Dead. She is the girlfriend of Brock Williams and an old muse of Ash. Lillian is played by Carmen Duncan.
Lillian probably lived in Elk Grove for the vast majority of her life. Ash mentions her a few times when he returns there and it is later implied that the two had an affair of some sort. Some time after Ash left Elk Grove, his father started to date Lillian and the two ended up in a relationship.
When the deadite start to invade Elk Grove she becomes one of their early victims. A now posessed Lillian goes to Brock's house to spend some time together. Ash soon returns from his adventure from the morgue and realises that Lillian is no more and she is a deadite. A brief struggle happens in Ash's room which ends with Lillian's final death.
The death of his girlfriend is just one more reason on Brock's long list of issues to hate and despise his son.