From Halopedia, the Halo Wiki
An Energy Cutlass is a Kig-Yar melee weapon. It is a shard of glass-like crystal and is pink in color. The Jackals use them primarily to dispatch enemies in close-quarters fights, especially when boarding an enemy ship. They are similar to the UNSC Combat Knife. These blades house a complex chemical mixture within them that causes the knife to explode into shards when embedded into a soft target, similar to a Needler round. These blades may be relics from an earlier time for the Kig-Yar culture or simply outdated Covenant weaponry that has since been removed or replaced by new weaponry.
- It is speculated that the Energy Cutlass is actually a round from the Needler, or at least made from the same material.
- Grunts also use them, as seen during the fighting on the Tiara during the First Battle of Harvest.
- The Energy Cutlass was believed to have been a new weapon used by Kig-yar in Halo 3, but was found out just to be a myth once the game was released.
- ↑ Halo: Contact Harvest