Rocky Wrench

Rocky Wrenches are a type of Koopa that attack foes by throwing wrenches. Rocky Wrenches work for Bowser's Koopa Troop, often appearing as guards on the organization's vehicles.

Super Mario Bros. 3
Rocky Wrenches first appear in Super Mario Bros. 3 as enemies on Airships, tanks and ships belonging to the Koopa Troop. Upon sighting either Mario or Luigi, a Rocky Wrench will pop out of its hole on these vehicles and throw wrenches at them, before descending back into their hole.

Super Mario Galaxy
Rocky Wrenches also appear in Super Mario Galaxy as enemies in the Gusty Garden Galaxy and the Battlerock Galaxy, where they attack by throwing wrenches, like before. If the player were to approach the trap door where Rocky Wrenches attack from, they will not surface, and only will if the player is some distance away. Here, the player must shoot a star bit at them from a certain distance or perform a Ground Pound to knock them over, and then jump on or star spin them to defeat them. The Rocky Wrenches in this game do not have shells on their backs like previous incarnations, so they look like Monty Moles who throw wrenches.

New Super Mario Bros. Wii
They also appear in New Super Mario Bros. Wii on the Airship of World 6. Their behavior is largely unchanged from their Super Mario Bros. 3 incarnation, though they can be frozen. However their appearance has been changed and they now resemble Monty Moles with goggles and no longer wear shells.

Mario Kart DS
In Mario Kart DS, Rocky Wrenches appear as obstacles on the Airship portion of the Airship Fortress; popping out of their holes at random; these Rocky Wrenches can cause a kart to spin out of control if they run into them.

The Adventures of Super Mario Bros. 3
On the television series The Adventures of Super Mario Bros. 3, Rocky Wrenches appear in several episodes, most commonly as the guards of Bowser and the Koopalings' Doomship, although they were also shown to work on tanks and the Doomsub as well. A Rocky Wrench, whose dialogue consists of nothing but menacing growling, has a somewhat prominent role in the episode "Up, Up, and a Koopa", where one is assigned by Bowser and Kooky von Koopa to guard the cage Emperor Ed, and later Mario and Luigi, are held captive in. He is bribed a Fudjie by Mario to free them, but declines.

Trivia

 * Rocky Wrenches look a lot like Monty Moles and use an attack pattern similar to them; they also have shells similar to those of Buzzy Beetles; this could make them a cross between the two.
 * A Sammer Guy by the name of Spanner of Rock appears in Super Paper Mario, his name and speeches including references to Rocky Wrenches.