Here are some possible interpretations:
* A poodle that's hard to find: Maybe someone is looking for a poodle that seems to vanish, like a phantom.
* A poodle that's imagined: It could refer to a poodle that someone is dreaming about or fantasizing about owning.
* A poodle with a mysterious past: Perhaps there's a story about a poodle with a secret history, making it seem like a phantom.
Without more context, it's impossible to give a definitive answer. If you heard the term used, it would be helpful to know the context.