It Follows- No Name

From https://collider.com/david-robert-mitchell-it-follows-interview/

Does “it” have a name? How would you refer to “it” on set?

MITCHELL: Everybody said different things. I’ve heard all kinds of stuff. We would just say, ‘Oh, those its.’ I’ve heard some people say, ‘Oh, it’s like the follower.’ I don’t really know. I never gave it a name, but sometimes we would refer to the different its by their physical description. You know, ‘the giant it,’ or whatever. That’s how we would refer to them.