Answer:

STREAKER

Answer	Crossword Clue
STREAKER	He takes off and then takes off
STREAKER	1974 Oscars intruder, notably
STREAKER	Runner sans duds

STREAKER	One barely running?
STREAKER	Nude runner
STREAKER	Running buff in the buff
STREAKER	Certain prankster
STREAKER	Fast mover
STREAKER	'70s faddist
STREAKER	One of flashing speed.
STREAKER	His end is in sight

STREAKER	Erstwhile campus cutup
STREAKER	Comet, e.g.
STREAKER	Person who can barely run
STREAKER	Runner in the raw
STREAKER	1973-74 faddist
STREAKER	70's prankster
STREAKER	1970's fad participant
STREAKER	Buff runner?

STREAKER	Campus prankster
STREAKER	Eye-popping runner
STREAKER	Stadium showoff
STREAKER	Participant in a '70s fad
STREAKER	Exhibitor of raw speed