|First appearance:||Book One|
|Tamer:||Ai and Mako Terada|
|Armour level 1:||None|
|Armour level 2:||None|
|Armour level 3:||None|
|Ultimate level 1:||None|
|Ultimate level 2:||None|
|Mega level 1:||Beelzemon|
|Mega level 2:||Beelzemon Blast Mode|
|Mega level 3:||None|
Impmon is a small humanoid imp Digimon with a tail and large pointed ears. He wears a pair of red gloves and a matching red bandanna.
In the beginning, Impmon was a trouble-making Digimon who had spent his time picking on humans. He harassed the Tamers and their Digimon (although Terriermon once fought him and sent him flying sky-high). Impmon seems to have some sort of distaste against the humans saying that "no self-respecting Digimon" would every ally to themselves. This proved as before, Impmon was the partner of Ai and Mako Terada, but he escaped as they continuously kept treating him like a toy. He also resents the Tamers and their Digimons because unlike him they can digivolve.
He tried to digivolve by seeing Indramon, despite Renamon's warnings only to suffer a defeat in the end. Being humiliated and having his ego crushed he accepts Deva Chatsuramon's offer. He could digivolve but only on one condition: he'd have to kill the Tamers. Very conflicted at this offer at first, remembering the kindness Guilmon had given, but nevertheless, he decides to digivolve.
And unfortunately, he gets blinded with thepower and goes on a murderous path, whom of which had cause Leomon's death. After a long battle against Gallantmon (Takato and Guilmon's biomerged form) he was defeated, and being shocked and ashamed at what he had done, he dedigivolved and left.
When the Tamers had to leave the Digital World, orders of Hypnos, Renamon decides to hunt for Impmon and she finds him. However, with Leomon's destruction this led to the D-Reaper to be formed. And after Impmon got back to Ai and Mako he reconciled with them and after they said they'd be by his side he admits to himself he loves them and he decides to unite with the Tamers to fight the D-Reaper.
After the D-Reaper was destroyed, he asked Jeri for forgiveness at what he had done, without knowing, and luckily she agrees leaving Impmon in peace with the humans.
In Book One, Jeri is still confronted with the loss of Leomon, and he feels responsible. After hearing that HYPNOS launched Project: Ressurrection which would revive Leomon he was rather surprised and scared to what he was going to say. After he was revived, he apologised for having killed him, and Leomon accepts the apology.
In Book Three, he actually pretends to be the Demon Lord Beelzemon in order to get close to Daemon, but his ruse was seen through fairly quickly. He also battles against the Royal Knights in Book Four, like Gallantmon who he didn't immediate realize wasn't Guilmon and Takato Biomerged until after the mega began to attack him.
Because he is difficult to be contacted, Impmon will sometimes miss out on important events, like Ryder's accident with the Mammothmon, because they can't find him. They also do not have any contact information for his partners, Ai and Mako, which meant that when Rayleigh Thompson begins his attack, no one could warn the young twins. This leads Impmon to be almost frantic with concern when he is stuck in the Digital World, unable to protect them or even know if they are unharmed.
Badda-Boom: Creates a small fire at his fingertips and hurls it towards the opponent.
Dark Fire: Attacks with a small ball of fire from the abyss.
Infernal Funnel: Creates two rings of fire, one within the other, which then creates a sphere of fire from the ring, which then hurls at the opponent.