Dupe Bug #1117open
vanilla - min: 1.7.10, max: 1.9.0
InventoryPets - min: 1.0.0, max: 22.214.171.124
Spamming the throwing action (right clicking) for the Banana Pet results in the item duplicating in your inventory. You can smelt down the un-damaged pet for gold, and as you can feed the pets until they are full health/undamaged you could keep duping the pets, healing them, and then smelt them down for gold.
The linked github report will say 126.96.36.199 instead of 1.4.9 because the issue was moved to a milestone repository for the update in which it was fixed.