Non-canon card

Triangular holofoil stamp

Secret lair card promoting The Walking Dead tv show.

In 2020, Wizards of the Coast introduced the concept of black-bordered non-canon cards. Although non-canon had been published before in silver border, the Secret Lair Drop Series: The Walking Dead release was the first time that cards from another IP appeared in black border.

That a card is not part of the Wizards of the Coast owned IP world is indicated a triangular holofoil security stamp.