Dark Souls Remastered | Gaping Dragon boss fight solo on NG+1 (NG+)

Drops:

75000 souls
Blighttown Key
1x Twin Humanities
1x Homeward Bone

Optionally, if you cut his tail off like I do here, you will get:

Dragon King Greataxe

The loot found in on the corpse in this boss arena includes the following:

Standard Helm
Hard Leather Armor
Hard Leather Gauntlets
Hard Leather Boots