Specialized shock infantry
- "Death from above!"
- — Unnamed Bullfrog, during the Siege of New Alexandria
ODST Air Assault units, often known as Bullfrogs, are combat teams of the Orbital Drop Shock Troopers Special Purpose Forces equipped and trained for the tactical use of Series 8 jetpacks. Members of these units are specialized in three-dimensional combat in dense urban and rugged natural environments, using aerial vectors to tactical advantage.
ODST Air Assault units were developed in response to the challenges presented by operations in both the dense, vertically integrated urban environments and rugged frontier terrains of the Inner and Outer Colonies. The Bullfrogs' specialized equipment and training allow them to traverse these difficult spaces with ease, using three-dimensional tactics to gain a combat advantage over enemy forces. Deploying from insertion pods or dropships, units of Bullfrogs are equipped with jump-jet packs which enable quick, thruster-assisted travel through difficult terrains of metal, rock, and vegetation. Bullfrog tactical doctrines uses these jet packs to execute series of bounding jumps, called "bounces", to clear buildings and terrain features in order to "cut off enemy troops, disengage to move behind cover, and quickly secure objectives". Sustained flight using jet packs is also possible, although slow, clumsy, and not tactically useful.
The Bullfrogs are part of the ODSTs' Special Purpose Forces, units of troopers whose additional training and equipment prepare them for unique and challenging combat scenarios. Bullfrog combat teams have been known to deploy with four or eight members. Like all ODST officers, ODST Air Assault team leaders are highly proficient, leading by example and through personal bravery. Committed to defeating the Covenant and protecting humanity, they accept the dangerous nature of their mission. They are usually veterans, who strengthen their already formidable Bullfrog units with their resolve and firepower.
In 2552, ODST Air Assault units were deployed during the Fall of Reach to conduct raids and direct action strikes against unsuspecting Covenant forces from the skies. During the battle, Bullfrogs skirmished with Covenant forces in the mountains outside Manassas. They also helped to protect civilians in New Alexandria. During the evacuation of that city, one unit of Bullfrogs helped SPARTAN-B312 to clear the New Alexandria cargo port and secure an executive landing pad at Traxus Tower.
- Though the ODST as a whole are heavily inspired by the Mobile Infantry from Robert Heinlein's novel Starship Troopers, the Bullfrogs show particularly strong influence through their extensive use of jetpacks. The Bullfrogs even refer to the use of jetpacks as "bouncing", a term used in the same context in the book.
- Despite being trained in the use of jetpacks, the Bullfrogs in Halo: Reach will never use their jetpacks except when programmed to do so in specific locations. Because of this, it is common for a player to have lost several members of his fireteam to falling by the end of the mission. Similarly, they often jump into large groups of Covenant forces and are quickly killed.
- It is possible that the 105th Drop Jet Platoon was an ODST Air Assault unit.
An ODST Air Assault "Bullfrogs" unit in Halo: Ground Command.