Pooka can refer to two distinct species from separate video games: in the Vanillaware game Odin Sphere, originally for the Playstation 2, Pookas are humans suffering under a curse that has turned them into a race of semi-anthropomorphic rabbits.
In the Namco arcade classic Dig Dug, they're those red and yellow things that kind of look like they're wearing goggles.

The name Pooka is traditionally derived from the Irish term púca, a type of spirit which often takes the form of animals such as rabbits. Another derivative is the English Puck, of Shakespearean fame.

For the Dig Dug species, use pooka_(dig_dug) instead.