A gorilla and his trainer have been together for 29 years, but their relationship is coming to an end.
"He's actually settled down a lot since his younger years. He was much more aggressive like these younger boys are," Houser said.
Houser dedicated hundreds of hours teaching Tubby, and the two built a special trust.
"Just to be accepted by an animal into their social group, that'll make a keeper's day, you know, that's a big deal," Houser said. "He's gotten to be so good."
Houser watched Tubby grow into a well-behaved, 430-pound silverback gorilla, perfect for breeding at the zoo in Philadelphia.
"He's actually going to a real good situation," Houser said. "I feel extremely good about what Omaha's done with the gorilla program and Tubby is an ambassador of that."
Tubby leaves early Thursday morning, and Houser says after so many years together, Tubby will be missed.
"Philadelphia is going to like him," he said.
Houser is flying Tubby to his new home. He said he plans to stay in touch with the zoo keepers in Philadelphia.