Animal lovers will be stripping off at London Zoo tonight (14 August) to raise funds to save the tiger.
Members of the public have been invited to unleash their wild side at the Streak for Tigers charity event.
Game participants are only permitted to wear trainers and body paint for the daring fundraiser, as they walk a 300 metre course through the zoo.
But, if you're not brave enough to bare all, you can always purchase a spectator ticket to watch the unique tiger parade.
Back by popular demand, the Streak for Tigers is turning into an annual event, with last year's naked run raising £40,000.
Speaking about the previous year's turnout, development director at ZSL James Wren said: "Everyone got so excited about the event, they really got behind it. There was an amazing buzz in the crowd, both from the spectators and the participants who were running around naked.
"We only asked them to do one lap, but many carried on doing several laps around the zoo because they felt so liberated and free."
Nic Coles, 34, from Biggin Hill, Kent, said it was "a great event".
"I was a bit nervous at first, but after seeing so many people turning out for it, it made it feel a lot easier. If it helps the tigers, I'd do it all over again."
It's hoped that this year's streak for tigers will be a roaring success.
All money raised from the Streak for Tigers will go towards conservation work to protect the Sumatran tiger. There are only 300 of the species left in the wild.