Voracious Greatshark

Flash (You may cast this spell any time you could cast an instant.)
When this creature enters, counter target artifact or creature spell.

Foundations

Foundations Jumpstart

Flash (You may cast this spell any time you could cast an instant.)
When Voracious Greatshark enters, counter target artifact or creature spell.

Alchemy Horizons: Baldur's Gate

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You can cast Voracious Greatshark without a target for its enters-the-battlefield triggered ability. That ability will simply not happen. It won't cause Voracious Greatshark to counter itself. It's not that hungry.