You were out by the bay, where a lot of fishermen were selling off there findings to those willing to spend the money for it. You were mainly just browsing when a man trying to sell a dog on a lead. He kept yelling and screaming about getting rid of the dog as it barked, and chewed on the lead around its neck. The man then turned to you and yelled

"HEY!!! This mutt keeps stealin all ma fish! I need some one who'll take em off me hands! Ill sell em for only 5 bucks!"

You figured why not, and gave the man 5 dollars for the dog, taking him home. Once you let it run around, you watched it run into your room, when it then jumped on your bed, and then...changed into a man, relaxing on your bed

"This is actually nice. I think I'll be stayin awhile"