Filed from 4 published puzzles

SKULL

Set to 4 different clues across 4 published puzzles, most often “Brain protector” — The New York Times, Monday, 3 July 2000.

5 letters

Every clue on record, most used first

Brain protectoronce
The New York Times — Monday, 3 July 2000
Jolly Roger depictiononce
The New York Times — Tuesday, 30 May 2000
Headonce
The New York Times — Friday, 3 February 1995
Head of the anatomy classonce
The New York Times — Sunday, 12 December 1993

Other answers to these clues

CFO3 letters
CRISIS6 letters
FOAM4 letters
FROTH5 letters
JOHN4 letters
LAV3 letters
LEADER6 letters
NOB3 letters
PATE4 letters
TOP3 letters
TOTOE5 letters