Boo Boo is described as gray with big yellow eyes, weighs 17 pounds, mean, old and cranky.
In Karen's Brothers, we learn that Boo-Boo was born into a litter of five kittens; he had four brothers and sisters. In Karen's Black Cat Watson told Karen that he had originally picked a a black kitten. He had picked her up and then the gray tiger-striped kitten came along and mewed. He stood up on his hind legs and batted his paws in the air. The man that ran the shelter said that he had never seen him do that before. Watson put down the black cat and it ran back to it's siblings but the gray kitten stayed behind. Boo Boo had cuddled and fell asleep in his arms and Watson had taken him home.
He would bite & scratch if he was provoked. He sometimes slept in the laundry basket. He slept & ate all day long. He hated Mrs. Porter, but okay with other people & animals. He was entered in the BSC Pet Show by Max Delaney and was surprisingly calm and happy when held by Max. Boo-Boo won "Best Personality."
Boo Boo was not allowed outdoors. He wouldn't set foot above the second floor because of Ben Brewer's ghost.