Spike Block

Spike Blocks are recurring objects that first appeared in Super Mario 3D Land.

Super Mario 3D Land
In Super Mario 3D Land, Spike Blocks appear in World 5-3 as clusters of smaller, blue blocks with yellow spikes (the same coloration as Spike Bars) on the front and top sides. They serve as hazards while riding the Lifts that move towards them.

Super Mario 3D World / Super Mario 3D World + Bowser's Fury
Spike Blocks reappear in Super Mario 3D World and Super Mario 3D World + Bowser's Fury as obstacles. They damage the player when they touch them. There are blue and red variants of Spike Blocks. The blue Spike Blocks are stationary while the red Spike Blocks move. Spike Blocks can be destroyed by Mega Mario, rewarding 200 points when they are destroyed.

Super Mario Maker 2
Spike Blocks reappear in Super Mario Maker 2, where they are placable objects found in the "Gizmos" category. It is only present in the Super Mario 3D World game style and is similar to the Spike Trap. There are three variants of Spike Blocks that can be used. Yellow Spike Blocks are on timers which cause the spikes to protrude and retract, functioning similar to the retracting spike obstacles seen in multiple levels in the original Super Mario 3D World such as Spiky Spike Bridge. The red and blue Spike Blocks' spikes can become inactive or active under the control of an ON/OFF Switch, and as such can be toggled. The player can stand on Spike Blocks when their spikes are retracted.

The Spike Block is currently the only course element in Super Mario Maker 2 to have had its category changed via an update. Prior to the version 3.0.0 update, it was part of the "Terrain" category, while version 3.0.0 made it part of the "Gizmos" category instead. This was most likely done to group it with the other ON/OFF Switch-affiliated items (like the Dotted-Line Block, Conveyor Belt, and ON/OFF Trampoline).

Super Mario Maker 2

 * North American website bio: "This is one block you do not want to hit. Combine it with the On/Off Switch to set a trap!"