In the play endgame, what makes hamm and clov different from typical dramatic characters?

In the play Endgame, Hamm and Clov differs greatly from typical dramatic characters. Hamm is considered a protagonist but he has an unlikable characteristic. Clov is also a protagonist in the play, yet he has a characteristic that differs from typical dramatic characters in which he is a servant and he wants to leave his responsibility as a servant. He desires to leave Hamm.