Clotho

Clotho (クロト, Kuroto), is a tamed slime monster owned by Kelvin.

Background
Clotho was once a regular Blue Slime until he got tamed by Kelvin.

Appearance
Clotho is a regular sky blue slime. Early in taking jobs from the adventurer's guild, Clotho, with his experience gains and the constant eating of defeated foes, evolved into a Slime Gluttonia, a legendary monster said to once almost destroy a country. Gluttonias can change their size at will, so Clotho can appear as a normal Blue Slime or as the massive slime monster he is.

Personality
A fun-loving glutton, who shows puppy-like affection towards Kelvin, He's known to love being admired by party members who tend to treat him like a pet. However, they understand he's a very loyal, fierce, and strong slime, and the very first creature in the new world that Kelvin made a contract with.

Titles
As a gluttonous slime, it wouldn't be far-fetched to say he gained the Title: Devourer very early on in the series, and accurate to the title, he's been known to eat almost anything, organic or inorganic.