This article is about the item. For the NPC, see Puffer Fish
A pufferfish can be caught underwater on Fossil Island. They are used to puff on to gain 15% more oxygen to stay underwater for longer. If the player has a fishbowl helmet equipped, it cannot be puffed, stating that "You ineffectually squash the poor puffer fish against your helmet".
Upon returning to the surface, all pufferfish in the player's possession will disappear.
Attempting to drop a pufferfish above water results in the message "The poor pufferfish expires with a lack of access to the sea.".
For an exhaustive list of all known sources for this item, see here