Lava Orc

Lava Orcs are a proposed species of orc. The most notable features about them are their ability to swim in lava and the fact that they have a "temperature": their abilities and resistances change according to this temperature, which is affected by numerous factors such as tension, water, and berserk.

Unlike most proposed species, Lava Orcs do actually exist in a playable state. Simply play the Erocrawl branch on CAO, and you can opt to be a Lava Orc. This is the branch of Crawl that was also the first testing ground for Octopodes: its master, Eronarn, is a prolific creator of content. Whether or not Lava Orcs will ever be merged into the main branch of DCSS is at this point unknown, but the developers have shown interest.