Fantasma

The expression "eres un fantasma (you're a ghost)" refers to a person boasting of having something or doing something, but in reality, he doesn't have it. The "fantasmas", in quotes, are people who try to impress others with lies.

People who are fantasmas often tell unlikely stories. Something implausible is something hard to believe, something you are sure cannot happen, something almost impossible. Fantasmas tell you these stories waiting for you to believe them, but it is very difficult for you to do so.

Dude 1: "So last week I went to Ibiza and met with hella amount of celebrities, like Ricky Martin, Matt Smith, Jhonny Deep, etc. so like, now I'm kinda his bestie and I talk with them all the time".

Dude 2: "Oh really, show me a pic of them with you".

Dude 1: #*internally screaming* Uhm, well, actually we didn't take any photos cuz they don't really like that".

Dude 2: "Yeah, right... vaya fantasma (such a ghost)".