Goat format ruling
Drillago

Card effect (current official text)If the only cards your opponent controls are face-up monsters with 1600 or more ATK, this card can attack your opponent directly.
Rulings
- If there are Spell/Trap Cards, or face-down monsters, on your opponent's side of the field, Drillago cannot attack directly.
- If Drillago attacks directly, and your opponent activates an effect to reduce one of his face-up monsters to less than 1600 ATK, there is no longer a condition allowing Drillago to attack directly, and a replay occurs.
- Q: When I attack with "Drillago" and all my opponent has on the fi eld is "Injection Fairy Lily," if he raises the ATK to 3400, can I attack him directly? A: You declare your attack during the Battle Step. Injection Fairy Lily is a 400 attack monster at the time, so Drillago would not be to use its effect and declare a direct attack. Drillago decides to attack the Injection Fairy Lily. Even if the effect of the Injection Fairy Lily is activated in the Damage Step, Drillago will not be able to change to a direct attack. Drillago will continue battling with the Injection Fairy Lily and damage calculation will occur.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Goat forum — sourced change requests get reviewed.