Many of you might recognize this keyword from a futureshifted card in Future Sight : The set ended up having too much frenzy, so the mechanic was one of the elements we removed
The keyword is no longer in use, but it's made some appearances in Master Editions and fun sets like Unhinged
Number 347 Language English Legal Formats Brawl, Commander, Competitive Brawl, Historic, Legacy, Modern, Pioneer, Standard, Timeless, Vintage Not Legal Formats Alchemy, Pauper Rulings (4/12/2024) Triggered abilities use the word "when," "whenever," or "at." They're often written as "[Trigger condition], [effect]." Some keyword abilities are triggered abilities and will have "when," "whenever," or "at the beginning of" in their reminder text
That, or they can just settle for looking at pixelated versions of the original Pokemon cards in the 3DS Virtual Console iteration of Pokemon Trading Card Game
Probably could use the site as a starting point
It can remove a smaller creature as soon as it enters the battlefield or immediately shut down a powerful blocker