If this card is sent to the GY as material for a Fusion Summon: You can Set 1 "Dracotail" Spell/Trap from your Deck, then you can destroy 1 Spell/Trap on the field.

If this card is in your GY: You can target 1 Spellcaster "Dracotail" monster in your GY; place this card on the bottom of your Deck, and if you do, add that monster to your hand.