Check out this serialized 224/295 Swords to Plowshares (NM) and this Wrenn and Six (NM) if you are into rare promo cards
While CGC Cards cannot prove that only 11 of these cards were created, it seems that the Prerelease Raichu cards were indeed accidentally stamped and then distributed to WotC employees as keepsakes without regard to any possible value they may hold
We did technically have another similar card, [[Mystic Meditation]], but this doesnt hold the name and also cost 4 mana rather than the 3 of the others
This can be tricky, but the Fossil item cards do have abilities that can help make this easier
Included cards in Celestial Guardians: Solgaleo a3-122-solgaleo-ex Solgaleo charges forward boldly
If there's a cost associated with having that creature attack, its controller isn't forced to pay that cost, so it doesn't have to attack in that case either