The Gitrog Monster requires you to sacrifice a land during your upkeep step. If you don't, you have to sacrifice the creature. Suppose that I have a land like Nurturing Peatland or a Creature like Squirrel Wrangler in play. Both of these permanents have an activated ability whose cost is the sacrificing of a land. Can I activate such an ability in response to The Gitrog Monster's triggered ability, during my upkeep step? If I can, and I do, will that meet the land sacrifice requirement of The Gitrog Monster?
(If sacrificing a land to The Gitrog Monster was the cost of an ability, this obviously wouldn't work since you can't pay a single cost to satisfy two different abilities. But there doesn't appear to be any ability associated with The Gitrog Monster's requirement to sacrifice a land during your upkeep step.)
While you can activate those cards to sacrifice a land, that will not satisfy the Gitrog Monster's trigger. That one you have to pay for when it resolves, during its resolution. The Monster isn't looking for a land sacrifice during your upkeep, it requires that you sacrifice a land specifically for its trigger (or sac the creature).
(If sacrificing a land to The Gitrog Monster was the cost of an ability, this obviously wouldn't work since you can't pay a single cost to satisfy two different abilities. But there doesn't appear to be any ability associated with The Gitrog Monster's requirement to sacrifice a land during your upkeep step.)
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