Counter target spell, activated ability, or triggered ability. (Mana abilities can't be targeted.)
"It is technically an ooze, but its life span measures only seconds. In that short time, its appetite for magic is extraordinary."
—Simic research notes
Near Mint - $800
Lightly Played - $600
Moderately Played - $600
Heavily Played - $500
Damaged - $400
Near Mint Spanish - $800
Lightly Played Spanish - $600
Moderately Played Spanish - $600
Heavily Played Spanish - $500
Damaged Spanish - $400