Builder is a fighting dog which belongs to the Tachibana family. Along with Yamato, he is Japan's World Championship representative.
Shiroi Senshi Yamato
The dog has been trained up to the extreme and it is really strong and durable. His special attack is Final Thunder.
Builder first fights against Big One which he easily defeats. Builder's next opponent is a dog named Londo, which also beats him. Builder was also supposed to face Yamato, but both dogs got rejected for fighting outside of the tournament.