The San Diego Zoo said the smallest giraffe ever born at the facility is growing out of his "pocket-sized" nickname at a rapid rate.

Obi, a giraffe born two months ago in the giraffe exhibit while zoo visitors looked on, stood at only 5 feet, 3 inches at his birth -- considerably smaller than the expected newborn giraffe height of more than 6 feet.

The zoo said Obi has since grown to nearly 7 feet tall, increasing from 117 pounds at birth to a healthy 270 pounds.

Officials said the "pocket-sized" giraffe doesn't appear to be suffering any ill health effects and is growing at the expected rate for an animal of his age.

"We were really excited when he was born," said Katie Tomlinson, senior keeper at the San Diego Zoo. "Of course, they're always cute, but him being smaller just makes him extra cute. And we just enjoyed watching him grow up -- watching his personality come out. He has a great personality -- really sweet, really curious -- so, it's been a lot of fun."