Sad to say but Mithril is a rare drop and usually I can only manage to find a piece or two per day and that's with me being level 50 and having a full board of animals, including those that drop Mithril. Don't be discouraged if you can't accumulate it quickly even by checking places that are known to drop it. Mithril is one of those things that you'll need desperately and struggle to find but once you start finding it a bit easier, you'll no longer need it, lol.
Below is the entry for finding Mithril from the HUB and a link to the HUB directly, it's a great resource and SW does an amazing job keeping it updated:
Mithril
Found: Mithril Dragon, deep mine, dark cave formation, Sir Pigglesworth, Jeweler Trade (rare), Armored Alicorn, Armored Manticore, Onyx Temple, Fey Courthouse, Dive into the Abyss adventure, Armored flyger, Mothraki Knight
https://forums.storm8.com/forumdispl...-Story-The-Hub