Grotle is a quadrupedal Pokémon with light green skin and a large shell covering its back. The shell is composed of hardened soil and conforms to the shape of Grotle's body, extending from its forehead to the tip of its short tail. The shell appears sectioned and is yellow with three long, brown ridges atop it. There are two bush-like trees growing around the outermost ridges. Grotle's lower jaw is yellow and has triangular extensions on the cheeks, while its upper jaw has a hooked tip. Its feet are yellow and have three claws each.
Grotle has the ability to sense where pure water wells up, and will carry other Pokémon on its back to these sources. It lives in forests but leaves during the day to allow more sunlight on its trees. Berries grow on the trees, attracting some species of Pokémon. In the anime, Grotle is seen to produce acorn-like nuts instead.
Grotle is the heaviest of the second-stage first partner Pokémon, at 213.8 lbs. (97.0 kg), being heavier than many other fully-evolved first partner Pokémon.
Grotle is the only second-stage Sinnoh first partner Pokémon to evolve at level 32. Monferno and Prinplup both evolve at level 36.
When Grotle evolves into Torterra, all of its stats increase by 20 points.