GamePress
Effect

When an opponent's monster declares an attack: Send 1 "Crystal Beast" card from your Spell & Trap Card Zone to the Graveyard to target the attacking monster; negate the attack, then you can add 1 "Rainbow Dragon" or "Rainbow Dark Dragon" from your Deck to your hand.

How to Obtain?
Character:

Trap Type
Normal
Trap Rarity
R
Card Code