Metal Oxy

 is a Tier 5 Tank that upgrades from Oxyrrhynchium at level 60.

Technical
The is just a debuff-immune Oxyrrhynchium. Notably, unlike other debuff-immune tanks, its projectiles also get debuff immunity. This is not particularly useful in the case of Acid, but it means its bullets cannot be slowed by Chiller branch.

Trivia

 * This tank was an idea by Wk18.
 * This tank and the Bessemer are the only tanks to be debuff-immune while also firing debuff-immune projectiles.
 * The bullets were originally designed to be dark gray, the shade of Metal Oxy's back spike.