How's It Hanging, Man?

I have some words for you to guess, perhaps a name or title.
It sounds like fun, but if you fail, I will turn homicidal.
To start, you get a set of blanks for letters (words are spaced).
Each time you guess a letter in the phrase, it’s duly placed.
Each time you get one wrong, I draw a portion of a guy
Who’s hanging from a gallows; if I finish him, he’ll die.
…Hey, wait a sec: With just one miss, the dude’s already dead,
Since nobody could long survive as nothing but a head.