Lock, Stock, and Barrel
There is a total of 48 barrels in the game. If you collect all 48 and feed them to Trico, you'll earn the gold trophy, Lock, Stock, and Barrel.
You can collect the barrels over multiple playthroughs if you need - but you must find each individual barrel. It won't do to feed Trico the
same barrels over and over.
Feeding Trico barrels will also unlock various costumes you can wear in New Game +. You can just feed Trico the same barrels over and over to
unlock these costumes. 96 barrels are required, over as many playthroughs as you need to collect that many, to unlock every costume and option.
I will mark barrels
with this formatting in the walkthrough to make them easy to find. Each one will include numbering to show the order I
found them, and to help you keep track of where you're at in your barrel hunting.