The Reference Book has this to say about:
The skin of the head of this Dinosaur Digimon has stiffened, and is covered with a beetle-like shell. Its entire body has been weaponized with things such as a huge horn and sharp claws, making it a very aggressive Digimon. However, Greymon is so highly intelligent that if you are able to tame it, there probably wouldn't exist a monster that's just as strong as it. Its special move of "Mega Flame" consists of it spitting out a super-heated flame from its mouth that burns everything down.
The pledge of "Nothing can stop the Twentiest! I will keep on running steadily!" was so engraved in Zubamon's heart that it has evolved into this being who sports a piercing style. Zubaeagermon has a policy of charging without stopping, regardless of whether the path in front of it is flat or treacherous, and despite doing so by crawling. Its special moves are "Road T(w)o Decade", wherein it stabs the enemy in the chest whilst yelling "Twentiest Twooooo!!", and "Vention", wherein it spins its entire body round and slices the enemy with the blade on its tail. Furthermore, when it transforms itself into a boastful sword, it can slice and defeat any kind of enemy with 100% of its power.