Reaper, Horrorween

Whenever Reaper enters the battlefield, it taps
unless you control an untapped Horrorween
creature.
Whenever Grim Reaper untaps, all opponent
players exile the top cards from their library
equal to the number of untapped Horrorween creatures you control.
{t}: Tap 2 target lands.
Opponent players can target Reaper directly
in combat phase, unless Reaper is tapped.