The Larva Race is a mini game in the Trool Fair.
It is found at (-10,-42). Talk to Fey Gnan to play, it costs 40 kamas.
The game is a luck based one. In it you are given the option to bet on which one of the four Larvae wins the race (the four Larvae from closest to the entrance are called Black Yama, Larvechen, Krok Larva and Kam Shuttle). Once you've picked your Larvae they race.
If you choose the right one you win 40 Trool Fair Tokens.