Terriermon is Henry's partner.
He often says "Momentai", which means "Take it easy"
He has the appearance of a small white and green rabbit with one horn on his head.
Introduction to Earth
Henry chose Terriermon as his character on the Digimon game. Terriermon fought Gorillamon as Gargomon and defeated him, chasing after him afterward. After nearly being killed in a battle, he came to Earth through the computer screen. After this Henry didn't want Terriermon to fight again.
When Takato met Henry and Terriermon for the first time, Terriermon told him he wasn't a good tamer if he couldn't keep track of Guilmon. He and Henry later broke up a fight between Guilmon and Renamon. When trying to do so a second time, Terriermon got in Renamon's line of fire and digivolved to Gargomon, losing his mind (as he was not ready for this kind of power yet) and nearly attacking Rika until Guilmon stopped him. Henry made him stand on his head until he dedigivolved.
When Gorillamon bio-emerged and beat up Guilmon, Henry was forced to let Terriermon fight him. In the end Terriermon destroyed his old enemy.
Terriermon also heard Impmon saying that Guilmon walked out on him when he was terrorizing people, and told Takato (who believed Guilmon was the culprit) this.
At one point Impmon tried to get Renamon to fight Terriermon by saying he called her a "fat-tailed bully", but she said he wouldn't fight because Henry has forbidden it. So Impmon thought he could attack Terriermon without him fighting back, but Terriermon hit him with Terrier Tornado. He later fought IceDevimon and was frozen, until Henry used a card to inflate him and shatter the ice.
Henry eventually decided never to let Terriermon fight again, although Terriermon wanted to fight another opponent. He forbad Terriermon from fighting Musyamon until Musyamon tried to kill a little girl and Henry, realizing some battles were worth fighting, digivolved Terriermon into Gargomon, retaining his mind for the first time, and Gargomon destroyed Musyamon, absorbing his data.
While at Henry's house, or in the presence of anyone who wasn't a tamer or Digimon, Terriermon would pose as a stuffed animal, and was often tortured by Henry's sister Suzie, who called him "Princess Pretty Pants".
Enter the Devas
Gargomon was the second one to fight Mihiramon, but was easily defeated with a tail whip. However he discovered Mihiramon circles like a shark before he attacks. Gargomon also fought Sandiramon in the subway and Sinduramon at the dam. All three Devas were destroyed by Guilmon in his forms of Growlmon and WarGrowlmon. He was later seen by Janyu during a confrontation with Impmon, whom he defended Janyu against.
Later Gargomon fought against Pajiramon, but she gained the upper hand, stomping on Gargomon no matter what Digi Modify card Henry used. Eventually Henry used the mysterious blue card they were trying to find the origin of, matrix digivolving him to Rapidmon, who destroyed Pajiramon and Vajramon. However, Vajramon came back to life, and beat up Gargomon along with Growlmon, but in the end Renamon destroyed him as Taomon.
Battle of Adventurers
Terriermon went with Henry on a vacation to take pictures of underwater ruins, but fought the evil Digimon Ebidramon. After digivolving to Gargomon and destroying him, he was taken to Omnimon's dimension along with Henry, Rika, and Kyubimon, and teleported to Mephistomon's base where they fought him alongside Growlmon. Eventually the three digivolved to their Ultimate forms and destroyed Mephistomon in his Mega form of Gulfmon.
The Devas, continued
Gargomon fought Indramon, helped Leomon defeat Kumbhiramon, and digivolved to Rapidmon for the third time to fight Vikaralamon. He, Taomon, and Vikaralamon were nearly killed when Yamaki activated Juggernaut, but after it was shut down by Makuramon, Rapidmon and Taomon stopped Vikaralamon's attacks while WarGrowlmon destroyed him.
When Makuramon kidnapped Calumon, Henry revealed Terriermon's true identity to Suzie before they, Takato, Guilmon, Rika, Renamon, Jeri, Leomon, Kazu, and Kenta traveled to the digital world to rescue Calumon. A data stream separated Rika, Renamon, Kazu, and Kenta, and so Terriermon and the others searched for them, defending the Forgotten Village from the evil motorcycle Behemoth before returning to the flag that marked the spot where they arrived, following Renamon's scent, and being transported to a warped area by an elevator where Ryo and Cyberdramon reunited them with Kazu and Kenta. Upon return to the main desert area, they fought Majiramon, whom Cyberdramon destroyed before leaving with Ryo.
Later, Rika and Renamon reunited with them, but this was short-lived when Caturamon sent Takato, Henry, and Terriermon into a data stream. They ended up in a cave in an underwater area, and discovered that in the digital world they can breathe underwater. After a misunderstanding and fight with Divermon, they entered a library where they talked to Shibumi, who sent them to reunite with the others on an ark.
When Terriermon heard Suzie transported to the digital world, he got the ark to change direction and crash in the Land of the Sovereign, where Antylamon became Suzie's partner and dedigivolved into Lopmon, who resembles Terriermon. When Beelzemon attacked, Terriermon matrix digivolved to Rapidmon to fight him, but was at a disadvantage. After the others were reunited, Kyubimon fought him but he destroyed Leomon. However it wasn't until he effortlessly destroyed Makuramon that Rapidmon and Kyubimon realized what a threat he was and decided he had to be stopped. Beelzemon used a variation of Makuramon's Primal Orb in an attempt to absorb Rapidmon and Taomon. Henry and Rika saved them with the Alias card, separating them from their Ultimate forms which were absorbed.
Later Terriermon took a hit from Caturamon to protect Suzie and Lopmon, and was nearly killed, falling into a crevice. Although Renamon got him back up, he slowly seemed to be dying from the injury, though he pretended otherwise. This caused problems when he was fighting Zhuqiaomon as Rapidmon, until Henry biomerged with him into MegaGargomon and seemingly defeated Zhuqiaomon. However, Zhuqiaomon returned, forcing the tamers to avoid him, until Guilmon and Terriermon jumped into the water. Zhuqiaomon tried to kill them but Azulongmon saved them and convinced Zhuqiaomon not to destroy the humans, instead focusing on the true enemy, D-Reaper.
After the tamers and their Digimon returned to Earth, Terriermon fought the D-Reaper and its agents, biomerging again as soon as Dobermon gave them the power to do so on Earth. He continued fighting the D-Reaper until they were forced to retreat for a week, after which Janyu uploaded Juggernaut into Terriermon so he could use it to devolve and destroy the D-Reaper.
Inside the D-Reaper's chaos, MegaGargomon, Sakuyamon, and Justimon fought Cable Reaper, who was blocking the portal that was vital to their plans. After the Sovereign removed Cable Reaper, MegaGargomon powered Juggernaut by spinning around in the center of the portal, sucking in and destroying the D-Reaper. However, due to Shibumi miscalculating his red card he separated. Kazu, Kenta, and MarineAngemon saved Henry, Terriermon, and the others from the void of Juggernaut.
Due to Juggernaut's side effects, Terriermon dedigivolved to his In Training form, Gummymon, and was forced to return to the digital world to survive. Takato later returned him and the others to Earth.
Terriermon was accidentally switched with Lopmon at one point, and fought the army of Parasimon, eventually biomerging with Henry to MegaGargomon. After Gallantmon destroyed the main Parasimon and the remainder of his gang, Terriermon attended Rika's birthday party with the others.
- Bunny Blast - Shoots a small energy ball
- Terrier Tornado - Spins into a tornado