Chimera

The Chimera is an orange revolver manufactured by Atlas.

Examples are on the talk page.

Special Weapon Effects
 A beast of many forms - Fire, Lightning and Poison  - Explosive x3 or x4. The bullets themselves deal explosive damage, but have a chance to be another element: incendiary, shock or corrosive. Consecutive shots can be the same damage type. It has a higher chance of dealing Fire, Shock, or Corrosive when aiming down the sight. It will usually do more explosive than any other element.

Trivia

 * The name is a reference to the chimera of legends, which has the head of a lion, the head of a goat extruding from its shoulder, and the tail of a snake/dragon/scorpion tail. Multiple forms, multiple elements.
 * The Atlas Chimera may have been inspired/based around the bow 'Ruins Edge' from the game Oblivion, which also had a random effect each time it was fired.