Draco Meteor (りゅうせいぐん Dragon Meteor Shower) is a Dragon-type move equivalent to Psycho Boost and Leaf Storm. It has a base damage of 140, and an accuracy of 90. Its power is based on the Special Attack of the user.
Draco Meteor is unique in the fact that it can be taught to only Dragon-type Pokémon, but any Dragon-type can learn it at any level, as long as it has maxed-out happiness. Arceus, although not a true Dragon-type, can learn this move only while holding the Draco Plate. Mew can't learn Draco Meteor, despite it saying that it can learn any kind of move.
In Pokémon Black and White, Drayden and Iris states that Draco Meteor is the "strongest Dragon-type move" when teaching the player's Dragon-type Pokémon. This indicates that with the exception of Roar of Time, which has a Base Power of 150, a signature move of Dialga, and the only Dragon-type attack slightly stronger than Draco Meteor, it is one of the most powerful Dragon-type attacks which can be used by any Dragon Pokémon with maximum happiness.
This is the only move which Mew cannot learn this is due to Draco Meteor being specific to Dragon Type Pokémon and Mew is a Psychic type.