Bristle is an enemy in Paper Mario: The Thousand-Year Door. It is a spiky rock monster that is nearly impervious when first encountered. It has spikes on its head and spikes on the sides AND it's impervious to fire. However, it does have a low attack power, so you have time to appeal to gain SP. The only way to defeat Bristle when first fought is to use a POW Block found in bushes outside the first fortress or use Defend and then Superguard it down. Later in the game, you can also use a special move, such as Earth Tremor. Bristles are seen again in the Glitz Pit in the group, The Poker Faces. They can't be hammered because they will stick their spikes out, damaging Mario.