Even though no such organisms exist, biologists use Darwinian Demons in thought experiments to understand different life history strategies among different organisms.
demon | Demon | Onimusha 3: Demon Siege | Wake Forest Demon Deacons men's basketball | The Demon Headmaster (TV series) | The Demon Headmaster | Demon Princes | Demon Knight | Demon Island | Six Demon Bag | Scream of the Demon Lover | Kamen Rider Kiva: King of the Castle in the Demon World | Demon with a Glass Hand | Demon's Claws | Demon Attack | South Carolina's Ieasia Walker drives to the basket against DePaul's Brittany Hrynko, while Blue Demon coach Doug Bruno | Running with the Demon | Refresh the Demon | Legion (demon) | Invocation of My Demon Brother | incubus (demon) | Hunted: The Demon's Forge | Evil demon | Etrigan the Demon | ''Demon Seated in a Garden'' | Demon of Paradise | Demon Lord Dante | Demon Knight (soundtrack) | Demon in a Bottle | Demon Days Live |