A vaguely
one-dimensional character in a TV show,
book,
movie, etc. who appears suddenly and by all rules of plot cliches should die but doesn't, or is the only character to survive after all the main characters are dead. See anticlimactic.
When
Helen killed
Cutter, Captain
Becker survived for no reason, proving his status as a pinkshirt.
When Harry killed Voldemort, he inherently turned all the remaining Death Eaters into pinkshirts.
Let's face it. Eight of the nine Ringwraiths are pinkshirts.