Edison Format · March 2010
Like all ignition effects, this card's effect can be activated whenever you summon a monster. When you summon Substitoad, you can activate its effect using your ignition priority. When the "frog" monster is summoned, Substitoad's effect can be activated again, using your ignition priority.
Tributing 1 monster you control is a cost.
The effect of "Substitoad" cannot be activated if you do not have any eligible 'Frog' monsters remaining in your Deck.