From Halopedia, the Halo wiki
The Echidna is a special variant of the Multiple Launch Rocket System-1 Hydra Gyroc Launcher. Named after the Lernaean Hydra's mother, it is featured in Halo 5: Guardians as an Ultra Rare REQ variant of the Hydra Launcher. Design-wise, it retains the Hydra Launcher's chassis but recolors it to a predominantly white color broken up by olive green and red stripes, along with an olive green falcon emblem in the middle part of the weapon on each side.
The Echidna is a named variant of the MLRS-1 HGL, upgraded to fire experimental, non-nuclear warheads capable of generating an electromagnetic pulse and have a second zoom level that can detect targets up to 2,040 feet (622 m) away. The weapon's experimental EMP-equipped warheads are just one of Chalybs Defense Solutions' many R&D projects. Another named variant, the Typhon, is also produced by the Watershed Division.
Halo 5: Guardians
The Echidna is an Ultra Rare Level 6 Power Weapon REQ that grants 150 REQ Points when sold. It operates exactly identically to a normal Hydra Launcher except that it has the ability to temporarily shut down vehicles with its EMP-equipped missiles within a 6.6-meter radius, and it can lock on to targets even when hipfired. Similarly to the High Five, the Echidna also comes with a strong secondary zoom level that allows it to seek out targets as far as 621.79 meters away. These traits make the Echidna an effective anti-vehicle weapon, especially during Warzone, where the player may encounter bosses in vehicles (e.g. Malevian Armsman). Conversely, it is less effective against infantry despite retaining its two-shot kill ability from the Typhon and normal Hydra Launcher, as it deals the least total damage out of the three (one direct missile is not enough to fully drain shields) and can only kill a full shield, full health Spartan with an entire magazine of 6 missiles aimed at the Spartan's feet in an extremely tight radius of 0.3 m (1.0 ft). Although it can detect targets as far back as 621.79 m, the missiles will disappear after approximately 1,000 feet (305 m), so unless the targets move towards the player, the missiles are unlikely to hit targets from extreme distances.
Changes from the Hydra Launcher
Halo 5: Guardians REQ cards
List of appearances