Atooin

Obtaining

 * Dropped by
 * Sphincter Cell

Uses

 * Used in the craft of
 * Atooin Ghost

Trivia
is named after Great A'Tuin, the turtle carrying the Discworld, from Terry Pratchett's fantasy series.

The description hints toward the Teenage Mutant Ninja Turtles and Master Splinter (here Sphincter Cell).

Atouin Tortuga Krötschild