Tigers are already an endangered species. This is a fact.
Then we have the Asian belief that the reproductive organs (in this case, the tiger's penis) are good as an aphrodisiac (or in other words, Viagra).
Then we have the phrase "humping like rabbits" or "going on like rabbits" or "reproducing like rabbits".
Tigers are fucking endangered... Rabbits are reproducing everyday.
See where I'm getting at now?
Why not the rabbit's penis as the aphrodisiac? It makes much more sense no? It's more widely available and because it's so widely available, it is the supporting fact that rabbits DO indeed reproduce more.
Don't mind me... I'm just being random and weird... splitting headaches since the night before would do that to you.
Oh, it will result in the following picture too:
Click for a clearer view...
Pictures from Google. Conversation from my twisted mind.