Why is it spelled tortoise and not tortiss?

Why is it spelled tortoise and not tortiss?

That’s a great question! I asked Zoya and she says that the spelling of tortoise is far more elegant that Tortiss. As elegant creatures, tortoises demand that all things associated with them be just as elegant as they are. Also, the iss in tortiss is too close to the hiss they make when they’re mad. They prefer the hiss to come as a surprise. It’s a turtpocalypse thing.