The Knick Knack Effect

An unexplained fear of a film (typically an animated one), a song, a toy, or any other object that a young child experiences when exposed to said object.

Patient: When I was a kid I was absolutely terrified of that pixar short Knick Knack but I never quite figured out why.
Psychiatrist : Sounds like you were dealing with the The Knick Knack Effect. it's more common than you think.