Tactimon is a major villain in the Digimon Mighty Squadron series.
Tactimon is the self proclaimed "Emperor of Evil". Thousands of years ago, he had left Lilithmon to takeover Earth while he pursues the conquest of other systems.
Tactimon arrives on the Moon, to punish Lilithmon, disgusted with her failure in defeating the DigiDestined. Stripping Lilithmon of her powers, he shrinks her & imprisons her within a "Space Dumpster," hurling her into the depth of space. He then mutates a piranha into the monstrous MetalPiranimon, who assumes command of Tyrannomon & Coredramon. The DigiDestined barely survive the attack, but manage to regain control of their Digimon. Furious, Tactimon attempts to destroy the five Digimon, only for the DigiDestined to turn the tables & digivolve the remains into the more powerful Thunder Digimon.
Despite the DigiDestined's acquisition of the Thunder Digimon, Tactimon attacks again & again, each assault deadlier than the last. His Digimon are created from objects on Earth with the power of his scepter, & he makes them grow using spherical grenades - Tactimon will throw the grenade down to the Digimon who will then catch it, pull out the pin & throw it to the ground to make itself grow. After his marriage to Lilithmon they will instead grow their Digimon by crossing their staffs. He once desires Maggie to be his queen based on her good looks & tenacity, & sends MadLeomon to capture, brainwash, & train her into being so, but his plan fails when it is discovered that the magic dust that is used to entrance her doesn't work & that she is really doing a Lilithmon impression to fool MadLeomon & buy the DigiDestined enough time to rescue her. Tactimon hates Maggie ever since.
Tactimon once attempts to create a team of evil DigiDestined, but Alex manages to free his enslaved group of humans before the plan takes place. He swears to erase Coredramon forever, finding him the most offensive of Lilithmon's mistakes, concentrating his attacks on him. He finally succeeds with Dokunumemon, wiping out Alex's power with Coredramon forever. He later plans to make Alex his successor by brainwashing him, but Seraphimon manages to get to Alex first, giving him his new Digimon Baihumon.
Over time, Tactimon discovers that the DigiDestined are no pushovers, & each of his Digimon fail to defeat them. With the Thunder Digimon & the new Digimon Baihumon at their side, the DigiDestined seem indestructible. He soon unearths the gigantic war Digimon known as Leviamon that is so large that it can crush the DigiDestined's Digimon with ease, however its flaw is that it uses up its energy so fast that it can only be used for short periods of time.
Soon it is time for Tactimon's Centennial Recharge, which he must undergo to fully restore his evil energies. It is during this slumber that Lilithmon returns to the Palace, plotting revenge. She pours a love potion created by Wisemon into the Centennial Recharge machine, & when Tactimon awakes, he instantly falls in love with Lilithmon, proposing. With Tactimon & Rita side by side, the battles with the DigiDestined are more difficult. Tactimon & Lilithmon's schemes together include creating a clone of the evil Alex & sending the DigiDestined back into the past. When SkullSatamon arrives, Tactimon is disgusted by the skeleton Digimon's stupidity, & will bellow with rage every time SkullSatamon calls him "Tack". Lilithmon's love potion is eventually removed from Tactimon thanks to MadLeomon, but to everyone's surprise, Tactimon loves Lilithmon anyway. During the Maggie fiasco when Tactimon holds her hostage to force the DigiDestined to use the Shogun Digimon in his service, Tactimon battles Alex personally to keep him from saving Maggie from an alternate dimension. This marks the only time that Tactimon battles a DigiDestined personally. Though Tactimon easily gains the upperhand against Alexander, Alex uses Toraclaw to shatter Tactimon's T-Staff, forcing him to retreat.
When Barbamon arrives on the moon, Tactimon is pushed to the side as Barbamon takes over in his search for the Zeo Crystal. He expresses disdain for his father-in-law, who constantly puts him down. Once Barbamon left after his army is defeated by the Aqua Warriors, Tactimon is ecstatic, & he resumes his attacks on Earth. The DigiDestined are soon turned to children due to Barbamon's Orb of Doom & all that stands in Tactimon's way are the Aqua Warriors. Tactimon manages to find a map of the DigiDestined's Command Center pointing out a weak point. He sends MadLeomon & SkullSatamon in to plant a bomb & steal the Zeo Crystal. They succeed, but before they can take advantage of it, the Machine Empire arrives.
With Lilithmon by his side & his lackeys MadLeomon & Oinkmon in tow, they slip into Earth when he realizes that a Hyperlock Chamber that he had been searching for for two-thousand DigiYears had surfaced in Tokyo. He frees the prisoner, revealing him to be the legendary villain Oozemon. He then unleashes him on the DigiDestined, hoping he'll finally destroy them.
However, when Oozemon returns & it turns out he hadn't destroyed the Rangers, Tactimon begins to berate Oozemon, which does not sit too well with the evil tyrant. Tactimon & Lilithmon are overpowered by Oozemon, & he miniaturizes them, trapping them in a snow globe, leaving Oozemon with his moon base & lackeys to do as he pleases.
However, when things begin to turn around for the DigiDestined, Tactimon & Lilithmon cheer the DigiDestined on, knowing full well that destruction is to come to Oozemon for crossing the DigiDestined.
When the Machine Empire arrive & attack, Tactimon & Lilithmon are forced to retreat, taking Leviamon to Barbamon's home dimension. They soon return, however, in a motorhome, plotting to overthrow King Drasil & destroy the Empire. The two forces clash on several occasions, neither gaining much ground. At one point, Fuujinmon has Alex brainwashed & about to kill the other DigiDestined, but Tactimon has Wisemon help free them to prevent a Machine victory. After a series of failed attempts, they finally manage to destroy the Royal House of Gadgetry with a bomb in the shape of a gift.
Tactimon, along with Lilithmon, makes a cameo apperance in Turbo: A Digimon Movie, when Mermaimon calls Lilithmon for advice on how to deal with the DigiDestined, she is subjected to Tactimon's snoring & Lilithmon instructing her to flee, rather than fight.