A very tough Red enemy, with high attack power and extreme attack rate, but slow movement speed and close range. It can be considered a weaker, much slower variant of Bore.
To defeat it early on, use meatshields with anti-Red units like Whale Cat along with Titan Cats. If you are a new player, don't let One Horn get too close to the Cat Base, since he'll easily be able to destroy it.
This enemy becomes less and less threatening as you advance in the game. You can also use him as a source of money. However, keep in mind that he can have very high strength magnifications in some stages (EX: Tiny Wings (Deadly)), allowing him to easily plow through your lines if you don't have any unit that can deal massive damage to it or slow/stop/knockback One Horn.
Loves to help people. Works part time at a fire station. However, as he is so slow on his feet, he never makes it to the fire on time.