Horsehead is the first boss you'll encounter in Parapa Palace. He is a large, armored knight with a horse-like head. His primary attack involves swinging his mace. He moves slowly but deliberately. The key to defeating Horsehead is to exploit his vulnerability when he attacks. When he swings his mace, his head (his weak point) is briefly exposed. You'll need to jump and strike his head with your sword. Be careful not to get too close when he's not attacking, as his mace has a decent reach. The Shield spell can be useful here to reduce damage if you mistime a dodge or attack. Focus on precise jumps and well-timed strikes. After a few hits, he will fall, granting you the first crystal. This fight is a good introduction to the game's boss mechanics, emphasizing timing and positioning.
While Horsehead’s mace-swinging tactics are archaic, his equine design serves as a primitive precursor to the armored, mounted combat featured in The Legend of Zelda: Twilight Princess.