"It likes to make its shell thicker by adding layers of tree bark. The additional weight doesn’t bother it."
Pokemon has shown time and time again that animals aren't the only things the team at Game Freak are able to make Pokemon from, the very objects around us can be a creature, including a pinecone. Yet, to think this Pokemon is harmless is wrong, in fact, you could argue it's one of the most dangerous Pokemon ever because one of its first moves is self-destruct. A fact that was shown frequently in the anime when Brock caught a Pineco.
Pineco's Basic Attacks are Tackle and Bug Bite, while its Special Attacks are Gyro Ball, Rock Tomb and Sand Tomb.