Spiky blocks are hazards in the game Headcase. Spiky blocks are square shaped, and a variation of the big blue blocks, although this time these big blue blocks are entirely hazards and not half-hazard half-interactive object.
Spiky blocks have almost the same appearance as big blue blocks - a square appearance, blue colored, and a mouth and eyes - except spiky blocks lack ears, hands, legs, and a rectangular appearance, which they don't have since the outer edges of their body are covered in spikes.
Spiky blocks have different attacks than those of the big blue blocks. Spiky blocks will appear as square blue blocks in walls which always stay stationary. In a timed sequence, they will become happy and cause spikes to rise out of all sides of their body. The spikes are lethal, and will kill Norman Noggin on contact.
The player can use the square blue blocks as a platform, like the big blue blocks, only they must move quickly to avoid being hit by the spikes. Spiky blocks appear throughout Headcase in different sizes, and often encountered in groups.