Whenever this creature becomes tapped, choose one —
• You may put a land card from your hand onto the battlefield tapped.
• Return target land card from your graveyard to the battlefield tapped.
Fields of battle turn to fields of grain.
(23/08/2019)
Scaretiller's ability is a triggered ability, not an activated ability. It doesn't allow you to tap it whenever you want; rather, you need some other way of tapping it, such as by attacking.
(23/08/2019)
Neither mode of Scaretiller's ability counts as playing a land. It can put a land card onto the battlefield even if you've already played your land for the turn, and even if it's not your turn.
(23/08/2019)
If Scaretiller becomes tapped while casting a spell or activating an ability, that spell or ability resolves after Scaretiller's triggered ability has resolved.
