elusive cat
An individual who has committed to something but whether or not they will show up is anyone's guess. Also someone who's priorities and character you can't quite pin down over a long period time.
John: Have you seen Anna recently? Do you know if she's coming to the event, she said she would be there.
Steven: I don't know man, she's an elusive cat.
Steven: I don't know man, she's an elusive cat.
elusive cat by Brice E December 1, 2016
Get the elusive cat mug.