Tosenbo

Tōsenbo are spiked, slug-like creatures from the star stage of the Space Zone in Super Mario Land 2: 6 Golden Coins. These creatures inflate and deflate at a regular interval, but are barely visible when they are not inflated. They are invulnerable when not inflated, so Mario should stay away from them; they can only be defeated using a Star or a fireball when they are in their inflated state. According to the Shogakukan guide, they may related to Unibō.

Perfect Ban Mario Character Daijiten
''' トーセンボ 種族 　アクア族 性格 　すぐにすねる 登場 ゲーム　ランド2 ''' しぼんだときを狙え  からだ全体にトゲを生やし、しぼんだり、ふくらんだりしている生物. 踏みつけても倒せないので、しぼんでいる瞬間に急いで通り抜けよう. ファイアなら倒せるぞ.

 Tōsenbo  Tribe: Aqua clan Disposition: Sulks easily Game appearances: Land 2 ' Aim for the moment when it's squeezed. ''A creature whose entire body is covered with spines, which swell and contract. You can't knock it down by stepping on it, so hurry through it at the moment it is squeezed. Fire will defeat it.''

Trivia

 * In the Perfect Ban Mario Character Daijiten, the picture of Tōsenbo in its entry is vertically flipped.