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 - $14.30
Lightly Played - $11.40
Moderately Played - $10.00
Heavily Played - $8.60
Damaged - $7.20
Near Mint Spanish - $14.30
Lightly Played Spanish - $11.40
Moderately Played Spanish - $10.00
Heavily Played Spanish - $8.60
Damaged Spanish - $7.20
Foil Prices
Near Mint Foil - $31.50
Lightly Played Foil - $25.20
Moderately Played Foil - $22.10
Heavily Played Foil - $18.90
Damaged Foil - $15.80
Near Mint Foil Spanish - $31.50
Lightly Played Foil Spanish - $25.20
Moderately Played Foil Spanish - $22.10
Heavily Played Foil Spanish - $18.90
Damaged Foil Spanish - $15.80