Remathilis
Legend
I only consider it an encounter if interacting with it has a reasonable chance of success. A hydra you can only overcome by avoiding might as well be a wall.That is reductive to the point of being snark.
So do you only consider it an encounter if a skill check is made or initiative is rolled?
Let me turn the question around: does an encounter with a creature that can only be overcome with avoiding warrant XP or not?