The winner is..Pikachu SF
There's a wide selection of these to collect, but this one was special as it promoted the GAME BOY game
Coven is an odd mechanic, in that the only shared feature among all cards with Coven is its requirement: no matter what that card's Coven ability is, it can only happen if you have at least three creatures with differing power (the first number in a creature's bottom right corner)
Kuribandit Season four introduced eighteen different Kuribohs and a weird mechanic where they all ate each other for no reason at all, and Kuribandit ended up being the one that we actually got in the TCG when all was said and done
However, this is not an effect that is limited to modern monsters, as some retro cards also have this powerful effect, and the most relevant of these cards is Gale Dogra
Ivy Pikachu Year Released: 1999 Set Name: Wizards Black Star Promos Card Number: 1 Last Sold For: $153.50 How Many PSA 10s: 365 Find this Pikachu on eBay here