Answer:
The Chile Chihuahua is 8 feet tall, and walks on two legs.
Explanation:
This creature uses its 12ft tail to attack its prey, only using its claws when necessary. This tail isn't any ordinary tail either, as this creature is no ordinary dog. The chihuahua's tail is spiked, and can shoot these spikes out like a porcupine, paralyzing its victims.
There's a short really weird myth I just came up with. Have fun.
