Hepburn acquired the fawn when she was working on the 1959 film Green Mansions. Apparently, the animal trainer on set recommended that Hepburn take the deer home so that it would get better at following the actress around, and the deer and she soon got attached to one another.
Pippin slept in a tiny custom bathtub made for him, and he accompanied Hepburn everywhere-including to the grocery store. Once he grew too big for the home, Pippin moved into Hepburn's backyard-a move that made the actress' Yorkshire terrier, Mr. Famous, much happier!
Source: Mental Floss