Wolsey

Wolsey was a cat given to the Doctor. Following his regeneration into a new incarnation (DW: Doctor Who: The TV Movie) and meeting up with Bernice Summerfield, the Doctor passed Wolsey to Bernice so that she could watch over him. (NA: The Dying Days)

Biography
Wolsey the cat originally belonged to Joan Redfern. She gave Wolsey to the Doctor to 'guard' him. (NA: Human Nature)

Wolsey was made into a 'person' when a Perfecton missile the ship with Bernice Summerfield are aboard. In the Perfecton-generated reality Wolsey was remade into a seven feet tall fully clothed cat with a large cavalier hat. (BNA/BFBS: Oh No It Isn't!)

Quotes
"When I was a kitten, I was tremendously gauche and ugly. The runt of the litter, what? To achieve style such as mine requires years of experience, the rough and tumble of the world." (Oh No It Isn't!)

"The king's balls get bigger every year." (Oh No It Isn't!)