Black Mask (黒マスク Kuro Masuku), formerly known as the Black Man (黒い男 Kuroi Otoko) in the original movie, is the main antagonist in the movie Doraemon: Nobita's Dinosaur and its remake Doraemon: Nobita's Dinosaur 2006.
Black Mask negotiates with Nobita to sell Piisuke to him as Piisuke trusts humans. Nobita disagrees and he will return Piisuke on his own era.
Then, Doraemon and Nobita successfully go back to that era though the black guy chases them. Nobita & Piisuke had a teary farewell to each other.
Later, Doraemon's group were attacked by a group of Dimorphodons but they were saved by Black Mask and he negotiate once again, this time with price and a free ride back to their current era.
Suneo wanted to accept their negotiate but Shizuka disagrees as they may be cruel to Piisuke. Suneo convinces Gian to be on his side but because Nobita save him from falling, he inspires Nobita's great heroine allowing Gian to take Nobita's side. Suneo accepts the fact & he will walk how matter they far they could.
The gang made a plan to fool Black Mask but they aren't succeed as Shizuka, Gian & Suneo were captured. Nobita & Doraemon are come to rescue them & Nobita lets Piisuke stay at his place.
The guys asks again to Nobita to give up his dinosaur as the T-rex will gonna eat his friends. But the negotiation failed as Piisuke awakened the Time Patrol Robots and soon the Time Patrols were coming. The Time Patrol successfully caught all the members from Dorumanstein's team including Black Mask.
Black Mask tried to negotiate to him several times but Nobita greatly refuses him.