There's Mongol the endangered snow leopard, who "frolicked" with Putin last year shortly after being rescued from poachers. He's now an official mascot of the 2014 Sochi Olympics.
And there's the polar bear who made headlines in 2010 when he was on the receiving end of a caress from the now-outgoing prime minister, who bravely fitted the heavily sedated animal with a tracking collar and admiringly called him the "master of the Arctic."
And then there's Serga, the Siberian tigress who was photographed with Putin after being tranquilized midpounce by the gun-toting, conservation-loving prime minister.
A video on Putin's website recounts the event, which took place when the tiger was caught in a trap set by researchers during a 2008 visit by the prime minister to the Ussuri reserve in Siberia.
"Vladimir Putin decided to walk closer to the trap, and appeared on the trail at the very moment when the tigress leaped out," the news announcer says. "He fired from a special tranquilizer gun, hitting the beast in the right shoulder..."
Putin later tagged the sleeping tiger with a satellite-tracking device. Since then, Serga has occasionally returned to the media spotlight with news of her own, most notably the birth of three cubs in 2009. (The "Vladivostok" newspaper ran the story under a banner headline reading, "After Meeting Vladimir Putin, A Tigress Has Given Birth To Three Cubs.")
But animal activists and the Russian blogosphere now say that Serga, commonly referred to as "Putin's tiger," is in fact a substitute cat -- and that the original tigress was not wild but rather a zoo animal who was borrowed for the stunt and later died as a result of a sedative overdose.
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Dmitry Molodtsov, a St. Petersburg-based ecological engineer, is the founder of bigcats.ru, a website devoted to tigers and other wild cats.
He says he has concluded from photographs and Internet articles that the actual tiger in the Putin pictures was not the wild Serga but Aralia, a zoo tiger who was sedated and held in a trap for nearly six hours before her encounter with the prime minister.
"When you look at various pictures of Serga -- the tigress they're now saying is Putin's tigress -- it's easy to see that the pattern on her coat doesn't change over time," Molodtsov says. "Depending on the time of year, a tigress becomes fluffier -- in winter, of course, her markings are more indistinct -- but nothing more than that. And the tigress who was with Putin -- and some witnesses have suggested it was another tigress, Aralia -- had completely different markings."
If true, the substitute-tiger story may further chip away at a reputation that Putin has built for himself as a thrill-seeking, nature-loving man of action.
In addition to his animal encounters, Putin has piloted fire-fighting planes, navigated a submarine, and retrieved ancient Greek artifacts from the bed of the Black Sea.
But not all of Putin's stunts have proven watertight. Late last year, Putin's own spokesman, Dmitry Peskov, admitted that the Black Sea antiquities miracle was an orchestrated event, but shrugged off the incident as "normal."
Nevertheless, Putin still has his defenders among the animal-loving community. Natalya Remennikova, the coordinator of the Siberian tiger-conservation project that Putin so famously participated in, says no substitute tigers were used in Putin's brush with big cats, and that Serga herself is alive and thriving.
"Serga was definitely the one who was tagged in 2008 with the help of the prime minister. This tigress is alive, and she's doing well," Remennikova says. "She's living on the territory of the Ussuri reserve. People who don't have reliable information -- especially people who don't know much about science -- try to make everything political."
Not everyone is convinced.
Molodtsov, for one, says after his suspicions about Aralia the zoo tiger, he has begun tracking the fate of Mongol the snow leopard, as well.
"I hope that everything with him is OK," he says with worry.
-- Anastasia Kirilenko and Daisy Sindelar