Advanced format ruling
Shield Worm
Card effect (current official text)When this card is Summoned, it is changed to Defense Position. Then, send 1 card from the top of your opponent's Deck to the Graveyard for each face-up Insect-Type monster you control.
Current rulings for this card are maintained by Konami.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Advanced forum — sourced change requests get reviewed.