Maestros Theater from your graveyard to the battlefield tapped.
Maestros Theater enters the battlefield, triggering itself and
Roaring Earth.
Resolve the
Roaring Earth trigger, putting a +1/+1 counter on
Cacophodon.
Resolve the
Maestros Theater trigger, causing you to sacrifice it and search your library for a basic Mountain, Island or Swamp and put it onto the battlefield tapped.
If you put a land onto the battlefield this way,
Roaring Earth triggers, putting a +1/+1 counter on a creature you control.
Resolve the
Scaretiller ability from step 1, dealing 1 damage to
Cacophodon.
Cacophodon triggers, untapping
Scaretiller.
Repeat.
Results
Infinite +1/+1 counters on
Cacophodon.
Infinite landfall triggers.
Put all basic Islands, Swamps, and Mountains from your library onto the battlefield.