Coral Colony
Creature — Wall
Defender
, 
: Target player mills X cards, where X is the number of creatures you control with defender. (To mill a card, a player puts the top card of their library into their graveyard.)
The seafloor is strewn with the wreckage of Vodalia's would-be conquerors.
Campbell White
Dominaria United (DMU)
• #45Rulings
The number of creatures with defender you control is counted when the ability resolves.
(wotc • 2022-09-09)
Rulings
The number of creatures with defender you control is counted when the ability resolves.
(wotc • 2022-09-09)