Super Metal Hippoe is a larger, stronger and faster version of Metal Hippoe. With its guaranteed knockback ability, quick speed, and high health, he can be a very annoying enemy to fight and will require proper Critical Hitters that outrange him.
It is important to note that like all other Metal Enemies, Super Metal Hippoe takes only 1 damage from any attack, unless it is a Critical Hit. As such, Critical Hitters are almost mandatory, unless you want a long, drawn-out battle. Space Cats work very well as they outrange Super Metal Hippoe, allowing them to be stacked to increase the chance of a Critical Hit. Marauder Cat is extremely effective against it, since it can land highly damaging Critical Hits.
Since this is an area range boss, you may want to bring less weak meatshields, and focus on spawning Critical Hitters.