One Dragon-type Pokémon that you might consider using on your Pokémon Go roster is Druddigon. It has some advantages over other Dragon types, and while it may not have an inordinate amount of stats, it's a solid choice to consider if you want to use it in the battle league. You have to consider the big question: is Druddigon good and how do you best use it in Pokémon Go?
Druddigon is a Dragon-type Pokémon. It is weak against Dragon, Fairy, and Ice-type attacks, but is resistant to Electric, Fire, Grass, and Water-type moves. Druddigon doesn't have the highest stats. However, he has a maximum CP of 2.732, an attack of 180, a defense of 146, and a stamina of 157.
Due to its lower CP, you should consider using Druddigon in the Great League, but it is also a suitable choice for the Ultra League. Both options are solid choices for Druddigon. However, Druddigon does not do well in the Master League due to his lower stats.
When it comes to the best moveset, you want to teach him how to move the dragon tail fast, with dragon claw charged moves and night cut. Both Dragon's Claw and Night Slash are charged moves that deal 50 damage and 35 energy. While having one of these moves is good, having two loaded moves that are spam makes it difficult to be a heavy hitter.
Due to its moves and stats, Druddigon is a solid Lead or Switch Pokémon. However, you don't want to rely on it as a Closer due to its lower defense stats. It's too weak to resist most Pokémon as a last line of defense, but it's an ideal glass cannon to use at the start of a fight.
Overall, Druddigon is a good choice in the Battle League, but it won't blow any other Pokémon out of the water.