Border Centering Pokemon cards have a distinct yellow border around them
One is currently listed on eBay for $1,000,000 Buy It Now at the time of writing and theres no information of previous listings or sale prices
Plus, Eye of Ugin gave Tron decks an inevitable late game, which would likely push them over the top at the moment, considering Tron is still near the top of the format even without Eye of Ugin
There are 8 in total: Diglett Dugtrio Poliwrath ex Phanpy Donphan Relicanth Dwebble Crustle These are all the Dark Type Pokmon cards from Secluded Springs
But this only works for cards found in main sets and to a lesser extent special sets since they're usually kept in production for a while (and if what TPCi said in the past is true, will continue to be printed as long as there's demand for 'em and they're not rotated out), this rule doesn't work for promos since they're usually only given away during a certain window of time and given a limited print run that's long enough to fit the predicted demand
Card frames are your best choice if you have multiple large Pokemon cards to display, as you can mount them in certain patterns to make them look more aesthetically pleasing