Answer:

TWIN

Answer	Crossword Clue
TWIN	Chang or Eng
TWIN	Duplicate
TWIN	Minnesota ballplayer

TWIN	Person who shares your birthday, absent some exceptionally rare timing
TWIN	Scarlett Johansson or Vin Diesel (who knew?)
TWIN	Exact duplicate
TWIN	Womb mate
TWIN	Matching
TWIN	Clone
TWIN	Castor, to Pollux
TWIN	Doppelganger

TWIN	Mirror image
TWIN	Mary-Kate or Ashley Olsen, e.g.
TWIN	Spitting image
TWIN	Bed mate?
TWIN	Identical
TWIN	Match
TWIN	Womb-mate
TWIN	Metrodome player

TWIN	Bed size
TWIN	.. Cities
TWIN	Romulus, e.g.
TWIN	2009 A.L. MVP Joe Mauer, e.g.
TWIN	Bed in old sitcoms
TWIN	Mattress size
TWIN	Sleeper's choice
TWIN	Baseballer named for two cities

TWIN	Bed with a mate
TWIN	Abby, to Ann
TWIN	Romulus, to Remus
TWIN	Mary Kate Olsen or Ashley Olsen
TWIN	Jacob, to Esau
TWIN	Matt Damon to Greg Kinnear, in "Stuck on You"
TWIN	Ann, to Abby
TWIN	Mary-Kate or Ashley

TWIN	Doublemint commercial actor, e.g.
TWIN	Jenna, to Barbara
TWIN	Double
TWIN	One of two of a kind
TWIN	One of two identical people