Greymon

Greymon is a champion level Digimon, that is a Beast type (others call it dragon type). Usually Agumon digivolves into Greymon, but depeding on the game and Agumons condition, this isn't always true. Greymon is known to be possibly the strognest champion digimon, and if not he's one of them.

Digimon Virtual Pet
Greymon was the second strognest champion (behind Airdramon) and he digivolves from Agumon. This was on the first Digivice which was released in 1997.

Digimon World DS
Greymon digivolves from Agumon at level 15 and 60 friendship, and can digivolve to MetalGreymon  at level 25 with 80 friendship.

Digimon World Dawn & Dusk
Greymon is #086 in Digimon World Dawn and Dusk, and is a Balance-class Dragon species Digimon with a resistance to the Fire element and a weakness to the Earth element. Its basic stats are 170 HP, 165 MP, 115 Attack, 92 Defense, 72 Spirit, 80 Speed, and 35 Aptitude. It possesses the Powerful 3 and Critical 2 traits.

Digimon World Championship
Greymon can digivolve from Agumon or BlackAgumon with 6 battles, and can digivolve to MetalGreymon  with at least 10 battles, MetalGreymon with 30 Vaccine AP and 8 battles or SkullGreymon if you pass time.

Attacks

 * Nova Blast   (Mega Flame): Spews ultra-high-temperature flames or a flame shot from its mouth to reduce everything to ashes.
 * Great Horns Attack   (Great Antler): Impales the opponent on its horns.
 * Grey Tooth
 * Great Tooth
 * Horn Impulse: Attacks the opponent with its horns.
 * Tail Crash: Slams its tail into the opponent.
 * Fire Wall: Spews out an encroaching wall of flames.