A unclear image of a Leeran.

The Leerans are a peacefull species from a planet mostly filled with ocean called "Leera". They once used the small contanant of Leera to mate and lay eggs, but their technology makes that unnecessary now, which is why they allowed the Andalites to detonate a shaped quantum explosive device, destroying a large Yeerk assault force.

Leera has a very interesting selection of marine life.

Animorphs Races Leeran by Monster Man 08

A Drawing of a Leeran (center) along with several creatures from Leeras ocean.