Is it a Frog or a Toad?

I don't know what he is, but, I miss him. He used to live in our little gold fish pond. I watched him grow from a tiny little non descript brown thing sitting on a lily pad into a big whatever he is over the course of 2 years. He finally got too big to hide in the crevices between the rocks. He's been missing for weeks. Maybe he moved into the big koi pond next door.