Penguin

Penguins are characters that appear in Cool, Cool Mountain and the slide sub-area, as well as Snowman's Land. They are needed for certain missions to obtain stars.

1996 Kellogg's Cereal Promotion
In 1996, Kellogg's Cereal had a promotional partnership with Nintendo, promoting Super Mario 64. Some boxes of Kellogg's mini-wheats contained artwork of the penguins which has been characterized as "disturbing" by some viewers due to the awkward 3D models used, which do not match the final version of the penguins found in Super Mario 64's full release.

As part of the promotion, Kellogg's Cereal also ran a mail-in giveaway offer where consumers could win 5-packs of Super Mario 64-themed lenticular 3D trading cards. One such card featured the penguins, and contained the following text: ""When you return the young penguin to its mother, Mama Penguin will offer to race you down an icy slope. When you beat her, she'll give you a star for your efforts. If you find that Mama Penguin is too slippery for you to catch as you rush down the slopes, look for a line of coins that runs into a wall. Follow the line of coins straight into the wall to find a shortcut to the end of the race!""

- -Penguins Nintendo Trading Card

Notably, this information is odd as it is completely false. While this shortcut exists, the Big Penguin will refuse to give Mario a power star if he takes advantage of it. Additionally, the penguin who is being raced in this mission is not Mama Penguin, but Big Penguin.

Shared Nightmares
Main Article: Shared Nightmares

Feeding Tuxie
Feeding Tuxie is a supposed anomalous mission that can appear in any of the snowy missions, most often replacing Lil' Penguin Lost. The baby penguin, Tuxie, will have their head facing upwards, similarly to a bird awaiting food, though this is often described as looking broken. Those who encounter this anomaly often describe having to bring some kind of item, often fish, to Tuxie, and give it to them, which will reward the player with a Power Star. However, some say that there is no way to complete this mission, rendering the mission impossible.

Standing Atop The Penguin
In certain copies of the game, the player is allowed to stand atop the penguin in Cool Cool Mountain, which is normally impossible. While this may not seem to serve any purpose at first (in comparison to standing atop the penguin in Snowman's Land), it is actually possible to ground pound the penguin to obtain coins, though doing this will also anger the penguin and make her chase the player around.

Child-Eating Monster
Main Article: Child-Eating Monster

In Super Mario 64 DS' files, an unused line of text believed to be for when Tuxie is swallowed by Yoshi can be found. "So it IS true that there's a monster that eats naughty kids..." This line is directly after the used text, so it might have been an alternate line of dialogue or the original dialogue before being replaced. Why it was replaced isn't known, but it may have been deemed too grim by the developers.