Can I counter a creature with Shroud?
Yes, Shroud on a card only works if the card is on the battlefield. In order to not be able to counter it the spell would have to have &quot;~ cannot be countered [by spells or abilities]&quot;.

702.18a Shroud is a static ability. “Shroud” means “This permanent or player can’t be the target of spells or abilities.”
110.1. A permanent is a card or token on the battlefield. A permanent remains on the battlefield indefinitely. A card or token becomes a permanent as it enters the battlefield and it stops being a permanent as it’s moved to another zone by an effect or rule.