Megatal

Megatal is a near-indestructible super-alloy from Sonic the Comic. It was developed in part by Tekno the Canary, on the orders to Doctor Ivo Robotnik, and used by him to create some of his most powerful badniks, including Shortfuse the Cybernik and Commander Brutus.

Megatal is incredibly strong. Shortfuse's Megatal armour protects him completely from damage from bullets or flame, and a self-destructing Trooper only caused minor surface scratches.

Super Sonic was once able to rip off Commander Brutus' forearm, but it is unclear whether this was purely because of his Chaos-enhanced strength or because that unarmoured part of the arm was made of a different metal.

Trivia
As an indestructible metal, Megatal is somewhat comparable to Marvel Comics' Adamantium.