Advanced format ruling
Mucus Yolk
Card effect (current official text)This card can attack your opponent's Life Points directly. Each time this card inflicts Battle Damage to your opponent's Life Points, increase the ATK of this card by 1000 points during your next Standby Phase. The ATK increase lasts as long as this card remains face-up on the field.
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.