- Not to be confused with Five-man Napsack, the treasure from which this item is obtained.

The Napsack is one of the items part of the Exploration Kit in Pikmin 2. It provides a quick method of returning to the Onions above ground or the Research Pod in caves, which is achieved by holding the X Button for a few seconds (C twice if you have Pikmin with you in the New Play Control! version) once it has been obtained. The Captain in control when it is used falls asleep, and any nearby Pikmin, up to a maximum of four, carry him to their associated Onion, a minimum of just one being required.
The Napsack's role is optional, since it is possible to return to the Onions or Research Pod on foot, but its practical application is that it saves time during the day. The pilot is carried back as quickly as if all flowered White Pikmin were holding him, regardless of which type of Pikmin is carrying him.
This ability is similar to that in Pikmin, which is activated by holding down on the D-pad (C twice if you have Pikmin with you, for New Play Control) . Up to five Pikmin subsequently carry Olimar away, in doing so rendering him impervious to attacks. If any Pikmin carry Olimar to one of their Onions, the Onion will spin like it is making more Pikmin, but it actually sends out fireworks and Olimar is safely returned to the ground. This function does not exist in Pikmin 2, even though the Pikmin can carry Olimar to an Onion.
If the Captain in the Napsack is picked up by a Dweevil and the beast wanders off the sublevel into the abyss, a glitch occurs.
Trivia
- The Napsack was originally named the "Treasure Antenna."