Norman
Norman (Japanese: センリ Senri) is the Petalburg Gym Leader in generation III. Although you encounter him first, he refuses to fight you until you have four badges, so he is the fifth to battle you. Once you conquer his Normal-types, he gives you the Balance Badge.
He is also your character's father, no matter which character you select to play. (Your rival will then be the child of Professor Birch.)
In the anime, he is the father of May and Max, and the husband of Caroline. In Pokémon Special, he is the father of Ruby, and his wife is nameless.
In Japanese, he is voiced by 小杉十郎太 Jūrōta Kosugi, and Dan Green in English.
In the Games
Norman has two sets of Pokémon teams, one in Ruby/Sapphire versions, the other in Emerald version. His Ruby/Sapphire team is simply a Vigoroth and two Slaking. In Emerald version, he starts out with Spinda, Vigoroth, Linoone, Slaking, but his team grows and evolves into Blissey, Kangaskhan, Tauros, Spinda, and two Slaking. In both versions, Norman has a Level 7 Zigzagoon he loans to Wally so that he can catch a Pokémon. He never uses it in battel, though.
Norman also provides special items scanned in via e-card reader to the player.