Atamadekachimon

Atamadekachimon is a Dinosaur Digimon. Its head and body are unbalanced. It is always having difficulty walking due to its heavy head, and completely destroys things when bashing its head about, even if it means no harm. It hates fighting, and is very motherly, constantly worrying about Minidekachimon, its pre-digivolution who it raises and protects within its mouth. It talks so loud that even Minidekachimon has to cover its ears, and gets even louder with the "-dekaa" it attaches to the end of its sentences. When Minidekachimon runs into danger, it fights for its life.

Attacks
 * Head Crush (頭つぶし): Swings its head down at the opponent from above with all its might.
 * Blast (鼓・爆砕): Restrains the opponent's movements by raising its loud voice to maximum volume.

Unison Attacks
 * Minideka Flame: Cooperates with Minidekachimon and spews flaming breath from its mouth, but it is uncertain whether the flames will be small or large until it comes out.

Etymologies
Official romanization given by the Digimon Reference Book and used in the franchise.
 * Atamadekachimon (アタマデカチモン)
 * (Ja:) Atamadekkachi (頭でっかち).

Digimon Adventure:
Minidekachimon, riding around in an Atamadekachimon's mouth, acts as the leader of a faction of Digimon fighting over a water source. When and  arrive looking for water, Minidekachimon captures Gomamon to punish him, but  rescues Joe and he and Gomamon lead Minidekachimon's forces to the water fountain where a brawl breaks out between the two factions. Minidekachimon and Atamadekachimon battle with before  smacks Gaossmon into Atamadekachimon's mouth with his tail, ending the battle.

After the battle, Tai and Agumon fish Gaossmon and Minidekachimon out of Atamadekachimon's mouth as the two factions finally reach peace.

Atamadekachimon is later amongst the many Digimon watching as darkens the skies of the Digital World and the  send their soundwaves to prepare for 's arrival.

DigiWindow
Atamadekachimon can be unlocked by communicating with the Digimon Pocket Wars cellphone game.

Notes and references
Atamadekachimon