The Pikmin ones roughly resemble a Pikmin's shape; however, they lack feet and leaf, bud or flower, and any identifying characteristics such as the Red Pikmin's nose. Their appearance is slightly transparent and they vary between the games. In Pikmin, every Pikmin has a blue spirit, irrelevant of the color of the Pikmin itself, while spirits in all other Pikmin games, including both New Play Control! remakes, are representative of the dead Pikmin's type, differing in color and slightly in shape.
If a Pikmin dies from being thrown into the abyss, it won't release any spirit in Pikmin or New Play Control! Pikmin, but it will in Pikmin 2 and New Play Control! Pikmin 2. In Pikmin 3, no spirit will be seen ascending from the abyss but it will actually be visible on the KopPad.
Enemy spirits have a pink-purple color and look like a bubble, and leave a transparent trail behind. Two holes resembling eyes are visible near the shape's center. Bulbmin produce a smaller version of this type of spirit when they die. However, enemies that do not really "die" do not leave a spirit when killed. This is the case for the Spotty Bulbear and the Gatling Groink, which can revive, and the Ravenous Whiskerpillar, which seems to remain alive even after being defeated. Enemies that die while petrified release a spirit, but these "non-dying" enemies do not.
In Pikmin 2 these spirits make an eerie sound when ascending. The sound is much deeper, and the spirit is much larger for bosses. In Pikmin 3, enemy spirits are blue instead of purple, have small white eyes, and have a small "tail". An enemy's death in this game means that the carcass is ready to be carried – the enemy cannot be picked up until the spirit is actually seen. Due to the way off-camera objects are handled, an enemy's spirit will not ascend until it is once again visible on-screen.
Although spirits aren't generally acknowledged in the main games, Captain Olimar's notes on the Abandoned Husk actually mention the spirits, describing them as "soul-like" things. The notes go as followed:
“It looks like an indigenous creature, but it's empty. Hmm. I've seen soul-like things leaving the bodies of other creatures. Did this empty shell once house a soul too? Did other objects we've found also once have souls? Where do they go? Who decides which creatures have them? Do I have one? Hmm... I'd better get some sleep. I'm running on empty.”