Nagu is a piscine Spectrobe which floats around in the air, staying airborne by using two fin-like wings. It has one large red and yellow eye in the center of its head, as well as two ribbon shaped antennae and small spines on its chin.
Spectrobes - "Nagu is pretty laidback and usually just floats around in the air. He stays airborne by using two fin-like wings. His solitary eye looks like a colorfully painted lens."