A last-minute phrase or word shouted out by enemies (particularly in a video game) who have just been dealt a mortal blow.
Based on 'catchphrase', except these would be those 'famous last words'. Sometimes deathphrases are uttered even after decapitation, etc.
"No More Heroes is awesome, but the enemies' deathphrases get annoying after a while-- who wants to hear 'my spleen!!' fifty-three times in a row?"