Drastic Putrescence

Put two wither counters on target artifact or
creature. (Whenever one or more wither counters are
put on a nonland permanent, if it has wither counters
greater than or equal to its mana value, its controller
sacrifices it.)
Flashback {2}{g}{b}
"Are you sure travelling in Ulvenwald will be safe?"
—Jyard Welsher, Nearheath nomad