This is a Knobbed Russet that I had the pleasure of eating recently. I'm not positive it was one, but it seemed to fit both the physical and taste description.
Some call it the ugliest apple, but I think a lot of the "ugly" apples actually look really neat!

It didn’t look that appetizing when I picked it off the tree, but once it was washed, it cleaned up really well.
I may have picked it a little late. The birds or insects seemed to really love the tree. I think it was the birds, as most of the apples looked like they had pecking damage. I didn’t look closely, but even the damaged ones still looked edible and weren’t rotting very bad due to the wound.
The birds have good taste in my opinion

, as I really liked these apples as well. The first bite was kind of shocking, an intense sweet/tart and good flavor, as I hadn’t tasted such an intensely flavored apple before. The flesh was kind of dry but pleasant in a weird way. I think it is probably one of the best apples I’ve tasted, especially if you like your apples with a strong flavor kick!
I started eating a slice, then another, and before I knew it the whole apple was gone, I was chewing around the core, and wanted more! I'd rather have a delicious, "ugly", highly nutritious apple any day over the tasteless, "perfect", mostly mealy apple looking things sold in most stores today!