- "An enormous snake that rules the Osohe Castle basement. Disturb its sleep and it will tidal wave you goodbye."
- — Battle Memory
The Oh-So-Snake is a boss in Mother 3, and the final boss of Chapter 2 in the game. The Oh-So-Snake is found by Duster, Kumatora, and Wess after falling into a large pool in the basement of Osohe Castle. It resembles a large pink serpentine with pupil-less eyes and a yellow underbelly.
In combat, the Oh-So-Snake possesses the ability to slap both Kumatora and Duster with its tail, using a biting attack on a single party member, and coiling around a party member, solidifying them. Later in the fight, it will dive into the water below, causing a large wave to hit both party members. The Oh-So-Snake can also waste turns making lots of bubbles. During the fight, the Oh-So-Snake's battle theme titled Formidable Foe will play, and it is the only enemy in the game to use this theme.
Its battle sound is Battle Sound 56 which falls under Code Numbers 927 for regular attack, 928 for Smaaaash! and 929 for Miss.
- The Oh-So-Snake's name is a pun on Osohe and the Japanese word hebi, meaning snake.
- The Oh-So-Snake is the only enemy or boss in the game to have the theme, "Formidable Foe."