Metal Hippoe is a stronger version of the regular Hippoe. Its attack rate is faster, and it has more attack power, along with an ability that only Metal enemies have: taking 1 damage per hit. At 100% strength magnification, it has 80 health in total, with 2 knockbacks.
In some levels, Metal Hippoe can act as an annoying meatshield, such as in Chubby. B. Goode and Prison Destruction, and other times it can be a help for stalling as you build up long-ranged cats.
While it may seem tough once you first encounter it, quick attackers, such as Giraffe Cat and Mr. are able to easily defeat it due to it's quick attack speed. Alternatively, you can use Moneko and hope for her to do critical damage. Later on, it will barely become a threat at all, as it's outshadowed by stronger Metal Enemies.