Each creature gets +1/+1 for each other creature on the battlefield that shares at least one creature type with it. (For example, if two Goblin Warriors and a Goblin Shaman are on the battlefield, each gets +2/+2.)
"Hup, two, three, four,
Dunno how to count no more."
—Mogg march
Near Mint - $15.600
Lightly Played - $12.500
Moderately Played - $10.900
Heavily Played - $9.400
Damaged - $7.800
Near Mint Spanish - $15.600
Lightly Played Spanish - $12.500
Moderately Played Spanish - $10.900
Heavily Played Spanish - $9.400
Damaged Spanish - $7.800
Foil Prices
Near Mint Foil - $38.800
Lightly Played Foil - $31.000
Moderately Played Foil - $27.200
Heavily Played Foil - $23.300
Damaged Foil - $19.400
Near Mint Foil Spanish - $38.800
Lightly Played Foil Spanish - $31.000
Moderately Played Foil Spanish - $27.200
Heavily Played Foil Spanish - $23.300
Damaged Foil Spanish - $19.400