Actress and HIV activist Zelda Rubinstein—best known for her role as diminutive psychic Tangina Barrons in the Poltergeist films—died January 26 at the Barlow Respiratory Hospital in Los Angeles, The Advocate reports. She was 76.

Rubinstein was one of the first celebrities to participate in an L.A. Cares HIV awareness campaign targeted at gay men. In the mid-1980s, she appeared on posters and billboard in Los Angeles as “Mother,” lovingly telling her sons to “play safely.” The campaign would later appear both nationally and internationally.

In addition to being an HIV advocate, Rubinstein also spoke out on behald of little people (she was 4 feet, 3 inches tall) and the LGBT community. She recently spoke with The Advocate about her advocacy work. Click here to watch the interview.