Spenser's physical being and heartbeat are as one with his Pokémon, his brethren. He has full trust in his Pokémon. He makes loud threats to set his opponent off guard. When defeated, he awards the Spirits Symbol.
"My physical being is with Pokémon always! My heart beats as one with Pokémon always! Young one of a Trainer! Do you believe in your Pokémon? Can you believe them through and through? If your bonds of trust are frail, you will never beat my brethren! The bond you share with your Pokémon! Prove it to me here!"
"Ah... Now this is something else..."
If the player is defeated
"Your Pokémon are wimpy because you're wimpy as a Trainer!"
After being defeated
"Gwahahah! Hah, you never fell for my bluster! Sorry for trying that stunt! Here! Bring me the thing!"
His assistant: "My, my, if only you could maintain that facade of distinguished authority... Here! Let's see your Frontier Pass!"
"Your Pokémon's eyes are truly clear and unclouded. I will eagerly await the next opportunity to see you."
"Gwahahah! You've battled your way up again? You must have developed a truly formidable bond with your Pokémon. So be it! This time, I won't bluster or hold back. This time, there's no fooling around. Ready now? Prepare to lose! ... ... ...Kaaah!"
If the player is defeated
"Gwahahaha! My brethren, we have nothing to fear!"
After being defeated
"Well, that was some display! Even fully unleashed, my brethren could not overpower you. You team spirit is truly admirable! Here! Bring me that thing, will you?"
His assistant: "My, my, if only you could maintain a certain level of decorum... Gaaah, here! Hurry with that Frontier Pass, you!"
"Gwahahah! Come see me time and again! My brethren and I will be waiting!"
Spenser debuted in Cutting the Ties that Bind. He found Ash's Pikachu lying along the riverbank and healed it with a natural remedy. Ash, his friends, and Scott later met up with Spenser, had a meal with him, and stayed overnight in the jungle while Ash continued to comfort Sceptile, who had been left heartbroken by an earlier rejection. The next day, Spenser and the others caught up to Ash just as Team Rocket arrived and stole both Pikachu and Sceptile. Ash managed to free his Pokémon, and after a Heal Bell from Spenser's Chansey, Sceptile sent the trio blasting off. Spenser and Ash then agreed rest up and battle the following day.
After a small snack break, the battle resumed. Ash selected Swellow, and despite having the aerial advantage, the Flying-type had to contend with Venusaur's Vine Whip and Razor Leaf attacks. Suddenly, the clouds moved and obscured the Sun, causing Venusaur's Solar Beam to take longer than expected. Swellow took advantage of the delay to knock Venusaur out. Spenser then sent out his Claydol, which quickly defeated Swellow. After another heated battle, Spenser and his Claydol eventually lost due to Sceptile learning and using Solar Beam.
Spenser has a simple life on Metallica Island, which allows him to appreciate its natural beauty. He believes in a natural order as well as the balance between humans and Pokémon. He has an extensive knowledge of herbal medicines and prefers to use local ingredients to create his meals.
In battle, Spenser prefers to use special attacks to overwhelm his opponent. He also uses the open-air battlefield's various weather conditions and landscapes to his advantage, making battles with him difficult. For example, his Venusaur's Solar Beam charges quicker when it is sunny, or his Claydol's Rapid Spin can trigger a devastating sandstorm.
This listing is of Spenser's known Pokémon in the anime:
Shiftry appeared in Ka Boom with a View!, where it was the first Pokémon to be sent against Ash, while he chose Sceptile. Before using any move, Shiftry dodged the Bullet Seed from Sceptile and was told to move to the jungle. It had immense speed, but Sceptile was just as fast, as it followed close behind. After the two Grass-types reached a small waterfall, both continued their duel. Shiftry managed to push Sceptile into the pool of water, then used Rock Smash to send rocks down into the pool. However, Sceptile escaped up through the waterfall and landed a hit on Shiftry, knocking it out, and winning Ash the first victory.
Claydol appeared in Ka Boom with a View!, where it was the third Pokémon to be sent out against Ash. Claydol had to face Ash's Swellow and Sceptile before being defeated by Sceptile's newly learned SolarBeam. Claydol is the powerhouse of Spenser's team, being able to use Rapid Spin in combination with Psybeam.
Spenser is one of the seven Trainers hired by Scott to be a Frontier Brain at the Battle Frontier. Spenser is first seen at the Frontier's opening ceremony, where he participates in a demonstration battle alongside Lucy. Though the battle ends in an easy victory, the ceremony is interrupted by Emerald, who announces that he wishes to conquer the Battle Frontier. The press mistakenly report the incident as allowing an ordinary Trainer to take part in the Battle Frontier before it officially opens a week later. The Frontier Brains decide to use this assumption as free publicity and allow Emerald to challenge the Battle Frontier under the condition that he completes it before it officially opens.
Later, while Emerald is challenging the Battle Pyramid, Noland is attacked by an unknown assailant and several rental Pokémon are stolen. After Noland is taken to a hospital, the other Frontier Brains begin to suspect Emerald as the culprit. They head to the Battle Pyramid to confront Emerald and find him after having defeated Brandon. When they ask him about what happened, Emerald reveals that he did not attack Noland and is actually after the Mythical Pokémon Jirachi. The Frontier Brains find Emerald's explanation suspicious, but decide to follow him into Artisan Cave, where Jirachi is currently located at. Upon arriving, everyone is attacked by a horde of wild Smeargle while Emerald continues inside to find Jirachi. After the Frontier Brains get past the Smeargle, they meet up with Emerald, who has managed to find Jirachi. Emerald attempts to capture Jirachi, but is attacked by Guile Hideout, the actual culprit who attacked Noland. When Jirachi runs off, Emerald attempts to pursue it, only to be attacked by the rental Pokémon Guile had stolen. Spenser, Brandon, Lucy, and Tucker all try to attack Guile to avenge Noland, but are easily defeated. Eventually, Jirachi escapes, forcing Guile to leave to continue his pursuit of it. Injured from the battle, everyone decides to return to the Battle Frontier. When they meet up with Scott again, he reveals that he was aware of Guile and Emerald's true mission the entire time. Scott states that he withheld the information from the Frontier Brains to help them get stronger as they still would have lost even if they had known of Guile beforehand.
The next day, Spenser encounters Ruby and Sapphire near the Battle Palace while Emerald challenges the Battle Dome. Spenser confronts Sapphire and reveals that he is able to tell that she came in contact with the Blue Orb in the past. The two Pokédex holders find Spenser's actions strange and leave to try and investigate. Shortly afterward, Emerald arrives to challenge the Battle Palace after losing to Tucker. Spenser agrees and decides to battle Emerald immediately without going through the usual sets of virtual Trainers. They are interrupted by a phone call, which is the others informing Spenser that Guile managed to captured Jirachi and is heading to the Battle Tower to make his wish. Emerald decides to head off to the Battle Tower and leaves his Pokémon behind to win the Spirits Symbol for him.
At the Battle Tower, Emerald battles Guile, but his spare Pokémon are defeated. Latios arrives and presents Emerald with his team and the Spirits Symbol they managed to win. Using his ability to share his sight with Latias, Latios relays a message from Spenser, who is still at the Battle Palace. Spenser reveals that in the past, he visited his friends, the guardians of the Red and Blue Orbs on Mt. Pyre. When they were away, he briefly touched the Blue Orb, which filled his head with images of the Legendary Pokémon Kyogre. Due to this moment of weakness, Spenser decided to train his spirit to prevent another incident from happening again. In addition to the visions, he gained the ability to tell when other people have touched the Blue Orb, such as Sapphire. Due to this, Spenser managed to find out that Guile not only touched the Blue Orb, but was someone who let its power seep through his entire person.
Guile is impressed by Spenser's skills, but uses Jirachi to wish for a gigantic Kyogre made of seawater to flood the entire Battle Frontier. Spenser and the other Frontier Brains work together to get the press to safety and fight off Guile's rental Pokémon while Emerald and the other Pokédex holders fight Guile. Eventually Emerald and the Pokédex holders manage to defeat Guile and destroy the gigantic Kyogre monster. The day after, an injured Spenser and the other Frontier Brains congratulate Emerald for the hard work he put into saving everyone.
Spenser and the other Hoenn Frontier Brains battle and defeat the Admins of Neo Team Magma and Neo Team Aqua, who had interfered in the launch of a rocket that was made to stop the meteoroid threatening to destroy the world. Later, Spenser and the other Hoenn Frontier Brains are called to Sootopolis City to assist in stopping the meteoroid.
Crobat is Spenser's first known Pokémon. It was used to battle a Swalot and Electrode in the opening ceremony of the Battle Frontier. Despite the type-disadvantage, Crobat, with the assistance of Lucy's Seviper, was able to defeat them. At the Artisan Cave, it was used to battle Guile, only for its attacks to be easily countered. Crobat was used to battle Emerald's team at the Battle Palace, but was eventually defeated. In the Omega Ruby & Alpha Sapphire chapter, it was seen helping Spenser fight the Admins of Neo Team Magma and Neo Team Aqua.
Lapras is Spenser's second known Pokémon. It was first seen taking Spenser and some other Frontier Brains to the Artisan Cave. It was later chosen to be one of the three Pokémon Spenser would use to battle Emerald at the Battle Palace, but it was eventually defeated. When Guile attacked the Frontier with his sea monster Kyogre, Lapras was used to move on the water and helped battle the rental Pokémon.