The Grindalid were a sapient species from a Galaxy Far Far Away that had a very unusual sexual dimorphism. Females where large-sized larva-like beings while males where smaller and more humanoid in build, albeit they had a segmented tail rather than legs. They came from a world whose dense atmosphere filtered out most light, and as such they could be easily burned and even killed by any source of light.
The most famous Grindalid was Lady Proxima, matriarch of the White Worms.