Metal One Horn has an extremely fast attack rate compared to hisvariants, but has very slow movement speed and pitiful range. He is a mid-tier Metal enemy; while his sizable bulk and rapid attack rate makes him a tough foe for players without Critical Hitters, his low range, speed and health allow most Critical Hitters to make quick work of him.
Metal One Horn has much higher HP compared to Metal Hippoe and Metal Doge, so Critical Hits are a must. Spam critters and meatshields to easily demolish him as his health is quite low.
Metal One Horn can demolish your units with his extremely high DPS. If he gets too close for comfort, it is recommended to send out Puppetmaster Cat and Showoff Cat, which can slow and freeze his movement, respectively. Mochi Cat won't help that much, as his DPS is too high even when weakened.