"I wondered if the Beast might be hungering for something...'Are you hungry?'"Barrels, sometimes called Trico Treats, are a collectible item found in The Last Guardian. They are important in keeping Trico happy and fed so that he and the Boy can progress.
Barrels are just that: wooden containers resembling half-barrels in dimensions (about 2.5 feet/.76 meters tall, 1.5 feet/.46 meters across, and a capacity of 15 gallons/56 liters). They seem to be filled with some kind of glowing blue substance that can satiate Trico-beasts with only small amounts for the beast's size. The substance seems to attract butterflies.
"I was more than a little surprised. I had not imagined for a moment that the beast could possibly wolf the barrel down whole."
Trico seems unwilling or maybe unable to find food for himself, thus relying on the Boy to procure the barrels for him. On finding the objects, the Boy must pick them up and carry them back to Trico one at a time. Once Trico notices the tasty item, the Boy can set the barrel before Trico, where the beast will devour it, swallowing the barrel and crushing it. The Boy can also throw him the barrel, where, most of the time, Trico will catch in and eat it. If Trico does not try to catch it and it hits him, he will emit a soft whine.
Barrels can be found in an area by looking for bright blue butterflies resembling the Menelaus blue morpho. If there is one butterfly, that means a barrel is close by. There are more butterflies the closer one gets to a barrel. The butterflies will follow the Boy as he moves the barrel.
After the Boy removes the spears from Trico's body, he compassionately decides to feed the injured creature to help it heal faster. While reluctant at first, the beast accepts the kindness. Once freed, the two set off. After this, at different points, Trico will stop, refusing to move again until he is fed a barrel (or sometimes several).
While it is not certain what is in the barrels, barrels can be seen being made atop the Citadel, where they are given by the Master of the Valley to the Armored Tricos when they bring it children to consume. There are fragments of barrels all over the highest chamber in the Citadel tower.
How to find Barrels
While most of the barrels are easy to find, especially the ones required to progress, not all of these collectibles are apparent. Here is a guide to find them all.