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.