Gragnol Adults are much more aggressive than their adolescent form. They have the ability to generate an energy shield, which repels all of Samus' beam weapons with the exception of explosive weaponry. Therefore, Samus must use her Grapple Lasso to tear the Gragnol Adults apart.
- "The large tail that characterizes Gragnol Adults is also their weakness: if pulled with enough force, it will tear them apart. An explosive blast will temporarily incapacitate them, making them easier to target. They possess the ability to generate an energy shield around their bodies, preventing Beam shots from damaging them. They are cunning predators, flying through their turf in search of unwary prey. They use bursts of Phazon energy to overwhelm their targets, and then swoop down to finish them. Maturity has provided them with a very durable exoskeleton." — Logbook "Gragnol Adult" (Metroid Prime 3: Corruption)