Mountree possess a large hardened soil shell that is similar to a tortoise's. On the shell are three trees that seem to be planted on small, mud-like hills, as opposed to the three shoots that appear on a Forestone's back. The soil shell is brown in colour and contains a few small yellow dots towards the middle that have the appearance of small pebbles. Its under body is a soft, olive-like colour part that is known to be a weak spot. The large shell gives them a lot of protection from even the strongest of enemies. It has clawed, stumpy legs that make it exceptionally hard for it to run fast and long distances. The rest of its body is green in colour, so that they blend in more with its surrounding forest flora. Its head possesses three small horns that give it an incredible boost in using head-smashing moves. Its eyes are marine blue which gives a less intimidating look to it, to show that it is the guardian of all the forest Pokémon.
Mountree has an exceptionally hard shell, even harder than granite. However, the weight of its hardened soil shell make it very slow. However, its speed can increase when it uses Rock Polish. The horn and armor on its head make it capable of using powerful moves that require the use of a HHead Smash . The small shoots on its back are actually trees, and they can shoot powerful sharp edged leaves at opponents from them.
Mountree are extremely brave and will attack foes that may be much more poweful than them. They are very protective over their home forests and will defend it at all costs. Mountree will never leave their forest. They often scare away forest pokemon from nesting on its shell.
Mountree will live in the forest that it had done since it was very first born. At this point of its life, it would most likely be the most strongest Pokémon in the whole forest and so will act as a guardian for all the forest life.
Mountree guards its forest from any danger, willing to risk its life to help those in need. Its shell is as hard as granite.