ST:DS9, If Wishes Were Horses, Episode 116
Oh god. Rumplestiltskin before the intro sequence. Prepare for shittiness.
Some bullshit physical phenomena causes peoples' imaginations to manifest physically.
Though, I do really like that Bashir conjured a copy of Dax, and got caught by the real Dax. Sort of hilarious to see real-Dax interacting with sexdream-Dax.