Arbok is a serpent like Pokémon with purple scales all over its body. It has a large hood just below its head. On its hood, it has a design much like an angry face, which can come in six variations. The pattern typically has red and yellow eyespot outlined it black, a wide black streak resembling a mouth, and a V-shaped stripe about the face pattern.
Arbok is capable of crushing opponents by coiling its body around them and squeeze them tightly. It can even flatten steel oil drums. If it encounters an enemy, it raises its head, mimics the opponent with the frightening pattern on its body and making eerie sounds by expelling air from its mouth. It has been stated that if any part of Arbok's body except for the head is cut off, it can regrow the rest of its body again in a matter of a few weeks. It also has the ability to detect vibrations. Arbok has been known to be capable of spending long periods underwater and surviving in aquatic environments. One particular Arbok could change its pattern at any time to increase power to different stats and get invulnerability to status conditions, if the pattern is uncovered.
Arbok is territorial. It lashes out at intruders with long fangs tipped with deadly venom. With a vengeful nature, it will not give up a chase once it targets its prey or an opponent, no matter how far. It makes its home in grassy savannas and plains. In the wild, it hunts smaller Pokémon, using the pattern on its hood to immobilize prey and using its toxic bite to finish them off and eat them.
Its design is likely based on an Indian cobra. Arbok and Ekans may also be inspired by the legendary basilisk since they were originally the only Pokémon to learn Glare. The basilisk was said to be a poisonous, serpentine dragon that would kill people with its stare, which may explain Arbok's place in the Template:Egg3.