Koopatrol

The Koopatrol are a variety of Koopas that appear in the Paper Mario series. Clad in spiky metallic armour, these Koopas serve as Bowser's elite guard. They are considerably tougher to defeat than standard Koopa Troopas as Mario cannot jump on them due to their spiked helmets. He can, however, whack them with his hammer. To attack, a Koopatrol will either charge at Mario and gore him with its helmet spike, or withdraw into its shell and rush at Mario.