The Lazy Shell is both Mario's ultimate weapon and an armor from Super Mario RPG: Legend of the Seven Stars. It is seen as a huge shell of a red Koopa Paratroopa.
In Super Mario RPG: Legend of the Seven Stars[]
Obtaining the Lazy Shell requires both the Seed and the Fertilizer. Afterward, Mario has to go to the northern part of Rose Town and enter the house where the gardener resides. Giving both the Seed and the Fertilizer causes a beanstalk to appear, which Mario can climb to go up to a cloud area with two treasure boxes. The first treasure box contains the Lazy Shell weapon while the second one contains the Lazy Shell armor.
Equipping the Lazy Shell weapon increases Mario's Attack by 90. It otherwise functions like the other shell weapons, but does 400+ damage if using a Timed Hit, or 300+ if not timed right. The optional boss Culex is very vulnerable to the Lazy Shell weapon.
The Lazy Shell armor can be worn by any character, and it greatly increases both their Defense and Magic Defense by 127 each, although at the cost of lowering both their Attack and Magic Attack by 50 as well as their Speed by 15-30.