Blue block
Blue blocks are stronger variations of standard blocks appearing in the Wario series of games.
In Wario Land 4, blue blocks[1][2] are stronger than brown blocks, and can only be broken by a Super Smash Attack or a powered-up Dash Attack. They may also be broken by jumping while in the Fat Wario transformation or when Wario jumps and hits it from below while in the Bouncy Wario transformation. Some blue blocks may reveal Bronze Coins upon being destroyed. Unlike ordinary blocks, blue blocks can't be broken in succession. Blue blocks often need to be broken to progress in a level, or to reveal a Diamond.
Alternate kinds of blue blocks[3] appear in Wario: Master of Disguise. They are a blue version of the red blocks which appear throughout the game and function similarly. However, unlike red blocks, Wario cannot destroy blue blocks with Dragon Wario's regular fire breath. Wario must obtain the Dragon Mastery Gem and turn his breath blue in order to destroy blue blocks.