Agent D, known as the Dimentor, is a dimetrodon agent who gets payed by Hawkon for his job and the secondary antagonist of A Dino Legend.
He first appears when Ally is imprisoned, ready to be eaten. The Dimentor then fights him and wins, telling him to leave the city so it will be easier to kill him. When he got the order from Hawkon to kill Ally he went to the future, eventually finding him on a cliff, fighting him and falling off.
He is similar to Rattlesnake Jake: They are both assassins who ask the heroes if they are hungry\thirsty.