A sledgehammer is a large, heavy hammer with a long handle, most often used for breaking up rocks and concrete. The long handle combined with a heavy head allows the sledgehammer to gather momentum during a swing and apply a large force compared to hammers designed to drive nails. Along with the mallet, it shares the ability to distribute force over a wide area. They have been used by various characters in the Teenage Mutant Ninja Turtles franchise as weapons.
In the 2003 continuity, Donatello chases Raphael with a sledgehammer after the latter destroys the Sewer Slider.
In the 2012 continuity, the sledgehammer is used by Tsoi as his primary weapon and as a tool for breaking and entering.
In the Panini comics, the sledgehammer is used by Tsoi as his primary weapon and as a tool for breaking and entering. It is also used by Slug as both a tool and an object for breaking and entering, until he was mutated.
In the IDW comics, Rocksteady used a long-handled sledgehammer while he was part of the Foot Clan. Rocksteady named the sledgehammer Juniper. Rocksteady also uses a similar hammer with the same name in video games based on this continuity, but it broke some time before the events of Splintered Fate. He "replaces" Juniper with a laser machine gun that he calls "Juniper Junior".
