The Insular Cave Rat -- Way to die out, loser!
Gastrocopta chichijimana -- A snail or something. What the hell was nature thinking?
Paleomastadon -- Sucked. Died.
White-winged Sandpiper -- Good job screwing up, evolution.
Mustela lutreola (European Mink) -- This thing is not only dead, it became extinct in the Netherlands. Pathetic.