City Gone Wild

City Gone Wild enters the battlefield tapped.
When City Gone Wild enters the battlefield, you
may discard and/or sacrifice X cards. If you do,
put X +1/+1 counters distributed and proliferate.
{t}: Add {g/u}{g/u}
"The Simic Combine expanded their territory vastly
after the war, always obliterating their enemies with proliferate. I tried to warn Selesnya and Dimir because
I felt bad, but they wouldn't listen. Tsk, tsk. Oh well!"
—Jace, Guildpact's Gaurdian