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
NM-Mint Foil - $17.90
NM-Mint Foil Non English - $17.90
Lightly Played Foil - $17.00
Lightly Played Foil Non English - $17.00
Moderately Played Foil - $16.10
Moderately Played Foil Non English - $16.10
Heavily Played Foil - $14.30
Heavily Played Foil Non English - $14.30
Damaged Foil - $11.70
Damaged Foil Non English - $11.70