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.