Lascaux

The  is a submachine gun found in Frostburn Canyon, submerged in a shallow pool in a cavern filled with Spiderant hives. A screenshot below marks the approximate location on the map, using the player marker.

Special Weapon Effects
Modified Dahl Burst-fire module: fires 9-round bursts that leaves a bullet pattern similar to the Lascaux cave paintings. Always spawns with a Double Mod and +100% Recoil Reduction.

Trivia

 * Lascaux is a cave system in France, famous for its well-preserved palaeolithic paintings of dun horses, Aurochs, and Megaloceros. Further reference can be inferred from the effect description ('The gun of the Bulls.'): Aurochs are an extinct predecessor to the domesticated cow.