Who is buck in ice age 3

Buckminster,also known as Buck or even Bu, is an insane,adult weasel that lives in the land of the dinosaurs.He has brownish-reddish fur with darker spots,a white chest, and a blue eye.He’s blind in the other,which he covers with a leaf-patch.He seems to have been domesticated earlier in his life, as his left ear has been ear-marked,and he made mention in the film that he had forgotten what it was like to be part of a family,faintly implying that he might not even have a family.He seems to recover some of his sanity by the end of the movie,and agrees to go with the herd to the surface, although he changes his mind and goes back underground.He is enemies with a meat-eating,mammal-hating dinosaur named Rudey,who almost killed him,but only blinded his right eye,upon which Buck angrily kicked out one of Rudey’s teeth,fashioning it into a crude knife and weapon.He was one of the movies new characters,but despite the fact that he seemed to become one of the favorite characters,he will most likely not appear in Ice Age 4,only being seen in the Ice Age 4 short film “Scrat’s Continental Crack-Up”,and even then only having a short cameo appearance.However,it is clear by the end of the movie that even though he never actually joined the herd physically,he is still considered by them to be a member of their “family”,as Crash and Eddie the possums show worry when they learn that Buck stayed underground and Manny the mammoth even carving him onto Peaches’s family mobile.
And so,as Buck once told the herd…

“The Buck stops here.”