One of Lance's Dragonair has to use Agility against Zubat as it is a Psychic type move (which is strong against poison types) and its only super effective move. Even a low level Zubat can easily defeat the Dragonair with a poison inducing move such as Toxic.
More research is needed for this article.
Reason given: Check if this happens in Generation II or other generations.
In Pokémon Red, Blue and Yellow, enemy Pokémon from computer controlled Trainers (but not wild Pokémon) prioritize super effective moves over regularly effective or other moves even if the move does not deal damage.
In Pokémon Red and Blue, all three of Lance's Dragonair know Agility as their only Psychic-type move. Agility is a status move rather than a damage dealing move, however, these Dragonair will be 'locked on' to Agility against a Poison type Pokémon such as Zubat, because the Psychic type is super effective against the Poison type.
A low level Poison type Pokémon could eventually beat one of Lance's Dragonair, and the process could be made quicker with a poison inducing move such as Toxic.
As enemy Trainers don't use PP in Generation I, Dragonair running out of PP on Agility is not a problem.
- A thread on Glitch City Laboratories Forums concerning the Move AI glitch