The Doodlebug is hidden in the middle of the second room; it may be poisonous, but is very easy to beat. As soon as it takes a hit from the top, it'll disappear. Grab The Key and hurry to the next level. If it re-hides before you get The Key, search around the middle of the level, particularly closer to the research pod; you should find it again.
A Watery Blowhog. Kill it quickly, grab The Key, and off to the hole.
A Fiery Bulblax. Take the 5 Red Pikmin and use both kind of sprays, or else you are almost guaranteed to lose Pikmin. You will make it just before the Bulblax turns normal. After its defeat, advance to the last sublevel. There are no buried treasures to look for.
A Burrowing Snagret resides here in the last sublevel. Use all the sprays you have left. Always aim for the head, its weak point. When it buries itself in the ground, wait for it to get stuck on emerging, so you have time to aim at the head. When its head is being attacked by a number of Pikmin, the creature will stop attacking to retreat.
Names in other languages