Shellshock resembled an enormous anthropomorphic turtle. Making use of a baseball bat, a large hook, and a set of brass knuckles, he also had a large-bore cannon concealed inside his shell. In addition to all of this, Shellshock had a set of magical traffic lights mounted on his back; this device was capable of casting either freeze or motion spells.
In an effort to impress Rita Repulsa, Squatt and Baboo created Shellshock with the aim of finally destroying the Power Rangers. After a battle in which he used his sorcerous powers to cause the Yellow Ranger to be unable to stop running, and to freeze the remaining Rangers, Shellshock was eventually robbed of it's magical abilities by the Yellow Ranger, who shorted out his traffic lights using the properties of daedra flowers.
Seeing her minion losing the contest, Rita used her staff of power to make Shellshock grow to gargantuan proportions, but the Rangers were able to use the combined might of both the Tyrannosaurus Dinozord and Dragonzord to end the monster's threat to humanity for good.