Back in my day, we didn't have these fancy cooking grills. When I was a young lad, you had to go out and catch your own yukkuri - and in those days, yukkuri were a lot meaner and harder to catch. Plus, you had to slow cook them over an open fire for a few hours while keeping them from fleeing. You young whippersnappers have it easy these days.
I don't think these are tako yaki things. They look more like the filled golden pastries (name escapes me at the moment), similar to taiyaki. The fillings are usually bean paste or custard, though there's flavored ones like strawberry-creme. usually 1 for 120 yen and 3 for 300 (depending on where you go).
Nah, not taiyaki. Those are specifically shaped like fish. I'm thinking of a general round one that they sell in a lot of the touristy-areas. I mentioned that because it looks like there's a cover too.
But yeah all of these instruments are pretty similar.