The file format used by the standard built-in InnoDB in MySQL 5.1 is the “Antelope” format, and the new file format introduced with the InnoDB Plugin 1.0 is the “Barracuda” format. No definitive plans have been made to introduce new features that would require additional new file formats. However, the file format mechanism introduced with the InnoDB Plugin allows for further enhancements.
For the sake of completeness, these are the file format names that might be used for future file formats: Antelope, Barracuda, Cheetah, Dragon, Elk, Fox, Gazelle, Hornet, Impala, Jaguar, Kangaroo, Leopard, Moose, Nautilus, Ocelot, Porpoise, Quail, Rabbit, Shark, Tiger, Urchin, Viper, Whale, Xenops, Yak and Zebra. These file formats correspond to the internal identifiers 0..25.