Not to be confused with Billy
- Double-Edge (Episode 34 - Bonus 5)
- Earthquake (Episode 31 - Bonus 5)
- Iron Tail (Episode 22 - Bonus 5)
- Protect (Episode 16 - Bonus 5)
- Roar (Episode 13 - Episode 16)
- Headbutt (Episode 13 - Episode 18)
- Metal Claw (Episode 13 - Episode 22)
- Iron Defense (Episode 13 - Episode 31)
- Take Down (Episode 18 - Episode 34)
- Billy Bob's role is to not only tank Physical hits well, but also deal nice damage back to the opponent. In addition, defensively, it uses Protect to bait in Special Attacks or Earthquakes that would normally beat Billy Bob while buying time for his partner.
- Chugga said that Aron taking 1 damage in his first battle is the new "It doesn't affect Misdreavus."
- Chugga caught Aron in Episode 13. He named him personally, saying he simply got the idea from the game's ridiculous-sounding Wild Pokémon battle music. He evolved into Lairon in episode 24 after beating Zook, and evolved into Aggron in Episode 39. His type is the defensive Rock and Steel, which is the subject of a running gag.
- He's the only Pokemon in XD Gale of Darkness to be caught in the PokeSpot.
- Chugga once said, "People have been telling me that Billy Bob is a stupid name. To that I say, Billy Bob has the most normal name in all of Orre besides my name!"
- Chugga was once upset that the first attack Billy Bob was hit with as an Aggron did 2 damage instead of 1 damage.
- At 793 lbs., Billy Bob is so far the heaviest Pokemon Chugga has used. However, Emile's Groudon is the heaviest Pokemon he has caught.
- Billy Bob is the first Rock-type Chugga obtained and his second Steel-type, the first being Walnut from Pokémon Colosseum.
- With a base 180 Defense stat, Billy Bob has the strongest Physical Defense of all of Chugga's Pokémon
- Billy Bob has the most amount of 4x Weaknesses, being Ground and Fighting.
- Billy Bob is the fifth Pokémon Chugga used capable of Mega Evolution, the others being Bulbapedia, Moegami, Altair, Pandora, and Psythe (who joined the group in the subsequent Platinum LP).
- This makes Billy Bob Chugga's only Pokémon outside the main series that can Mega Evolve, The Others are all from the main games.