Cardboard boxes are obstacles in a few of the Pikmin games, first appearing in Pikmin and returning in Pikmin 3 and Pikmin 4. They usually block a pathway, and if enough Pikmin cooperate to move the cardboard box between a ramp, it can be walked upon and used as a bridge.
In Pikmin[]
A cardboard box appears in every area except for The Forest Navel and The Distant Spring. Bomb Rocks can be found inside the box at The Impact Site, as well as the one found in The Final Trial in Challenge Mode. A minimum of ten Pikmin are needed to push a cardboard box, indicated by a 10 at the bottom right of the front side of the cardboard box.
In Pikmin 3[]
A minimum of twenty Pikmin are needed to push a cardboard box, and to reflect this, the front side has been updated to depict a 20 at the bottom right corner, instead.