Ken McCloud, holding a boa constrictor, spent more than 20 years with a U.S. Fish and Wildlife Service Special Ops team that specialized in long-term undercover operations.

Ken McCloud, holding a boa constrictor, spent more than 20 years with a U.S. Fish and Wildlife Service Special Ops team that specialized in long-term undercover operations.

Timothy Archibald-for The Washington Post

McCloud handles an iguana. One federal official says U.S. agencies seize about $10 million in illegal wildlife each year. There are about 200 USFWS special agents, but fewer than 10 work undercover.

McCloud handles an iguana. One federal official says U.S. agencies seize about $10 million in illegal wildlife each year. There are about 200 USFWS special agents, but fewer than 10 work undercover.

Timothy Archibald-for The Washington Post

McCloud's love for animals developed early. His expertise with reptiles prompted his first job offer -- in his teens.

McCloud's love for animals developed early. His expertise with reptiles prompted his first job offer -- in his teens.

Timothy Archibald-for The Washington Post

An Exuma Island ground iguana, one of seven McCloud confiscated during the long-term Operation Chameleon.  Posing as  a reptile trader named Mark Phillips, McCloud helped take down some of the world's most powerful illegal reptile dealers.

An Exuma Island ground iguana, one of seven McCloud confiscated during the long-term Operation Chameleon. Posing as a reptile trader named Mark Phillips, McCloud helped take down some of the world's most powerful illegal reptile dealers.

Tad Motoyama- Los Angeles Zoo

A gila monster in the care of McCloud, who earned the nickname "Doc" for his talent for reviving sick and injured animals.

A gila monster in the care of McCloud, who earned the nickname "Doc" for his talent for reviving sick and injured animals.

Timothy Archibald-for The Washington Post

Australian black-headed pythons at the home of Frank Lehmeyer, suspected leader of a smuggling ring targeted in Operation Chameleon.  An Angolan python is on the bottom of the cage. McCloud worked tirelessly over several months to build contacts and gain Lehmeyer's trust.

Australian black-headed pythons at the home of Frank Lehmeyer, suspected leader of a smuggling ring targeted in Operation Chameleon. An Angolan python is on the bottom of the cage. McCloud worked tirelessly over several months to build contacts and gain Lehmeyer's trust.

German Law Enforcement and Ken McCloud

Three adult Madagascan tree boas were shipped to McCloud. The 17-hour days and stress began to take their toll on the agent; he was cautioned to reduce his work hours.

Three adult Madagascan tree boas were shipped to McCloud. The 17-hour days and stress began to take their toll on the agent; he was cautioned to reduce his work hours.

Special Agent Ken McCloud

A rare and internationally protected blue vanda orchid, which McCloud bought for $500.  The rarer a plant or animal becomes, the greater its value on the black market.

A rare and internationally protected blue vanda orchid, which McCloud bought for $500. The rarer a plant or animal becomes, the greater its value on the black market.

David L. Martin

E. woodii cycads from South Africa were smuggled into the United States to McCloud during Operation Botany.  Cycads flourished during the Jurassic Period, but only about 300 species survive today. Some rare wild species can command a $60,000 price tag.

E. woodii cycads from South Africa were smuggled into the United States to McCloud during Operation Botany. Cycads flourished during the Jurassic Period, but only about 300 species survive today. Some rare wild species can command a $60,000 price tag.

David L. Martin

A warehouse full of South African cycads. For Operation Botany, McCloud went undercover as Marty Sterns, who ran a San Francisco-area commercial landscaping company that specialized in cycads.  Lifting such heavy plants left McCloud in pain, which led to two back surgeries.

A warehouse full of South African cycads. For Operation Botany, McCloud went undercover as Marty Sterns, who ran a San Francisco-area commercial landscaping company that specialized in cycads. Lifting such heavy plants left McCloud in pain, which led to two back surgeries.

Special Agent Ken McCloud

McCloud with a gila monster. McCloud is retired from the Special Ops group and now works part time as a special crimes investigator at the Peninsula Humane Society near San Francisco.

McCloud with a gila monster. McCloud is retired from the Special Ops group and now works part time as a special crimes investigator at the Peninsula Humane Society near San Francisco.

Timothy Archibald-for The Washington Post