Wait I am getting ahead of myself, Firstly you will be transported to a fantasy world full of magical and mythical creatures, like dragons, orcs, mermaids, goblins, Naga, and Minotaur to just name a few. Now then every time you lie you will gain the genitals of a random nonhuman creature. Then after time you will become hornier and you will start playing with yourself. And the more you play the more you will change into the creature or animal. And the more you change. The more hornier you will get. Until you finally can't take it, you stop everything and start searching for an animal or creature to get satisfied with. Like if you started to be turned into a pig. When you can't take it anymore you will search to find a pig to fuck you or you to fuck it."
Also if you become something small like a rat or insect you will turn into a giant sized one instead of a normal sized one. So you won't gain a millimeter long rat penis or something, it will be normal sized.
"Oh but it won't end there. And when you finally are turned all the way and was fucked or did the fucking you will then be turned back to normal only to repeat the process the next time. Each animal I am guessing will take a week or so. However every now and then even when you have sex with the animal you still won't change back, you will only change back after you live out the creatures life however long that may be, up to a limit though of 50 years, don't want you to be stuck as one animal for too long. No one will find this normal so you may eventually have to hide out in the woods or something."
"Oh you sick BAS!"
"But wait there is more!. Now for the Dare! For your dare, firstly you will slowly, as you change, take on the instincts of this animal, but don't worry you will always keep some humanity. Secondly you will hang up the phone and forget this ever happened." Jennifer heard some laughter over the phone and then a click. And then everything went black.