Spike Blop

Spike Blops are Spiny-like creatures who inhabit Bowser's body in Mario & Luigi: Bowser's Inside Story. Their slimy teal bodies are protected by red shells covered with spikes. They can only be damaged by hammers and some special attacks. Mario and Luigi cannot jump on them in battle to attack or even in the field to trigger a fight, as they will simply land on the spines, take one point of damage and most likely forfeit their turn; the two special attacks Spin Pipe and Magic Window, being jump-based, cause the heroes to meet a similar fate. Spike Blops attack by shuffling across the screen towards a bro and must be knocked back by a hammer swing, dealing counterdamage. They also will sometimes crawl along the ceiling to fall spikes first on Mario or Luigi; their shadow indicates where they are aiming. This attack is countered with a hammer swing as well.

Trivia

 * Their name might be based off of Spike Tops.