Mimics can also "drop" the Symbol of Avarice (the item will appear in its mouth and be normally lootable) when throwing an Undead Hunter Charm at them, so the item can be easily and safely farmed without killing the Mimic. Each time a Mimic chest is put to sleep by the Undead Hunter's Charm it counts as a separate roll, so you do not need to rest at a bonfire each time. (I just tested this assumption with 35 undead hunter charms and 260 item discovery on the two mimics outside Yhorm the Giant's boss room and I did not receive the symbol.) [I was running 311 item find and it took me around 40 Undead Hunter Charms but i did get the Symbol of Avarice using this method][Solvaring: I had 266 item find using covetous gold, crystal sage rapier, and rusted coin, read this here on the wiki. I remembered I left the two mimics alive outside the yhorm boss room having only grabbed the items from them using the hunter charm. I got it on my first try after having bought over 50 hunter charms for the farming run i thought was ahead of me. Confirmed.][Took me 4 tried with 109 item discovery at the chest under the dragon in High lothric. It's just luck but very much possible.]