Ally with Info

In Super Mario 64 DS, a Toad mentions that there is an "ally with info" within the mirror room of Princess Peach's Castle the player should find. This dialogue occurs, even with Wario, who is unlocked within the mirror room. Several theories have arisen about this supposed ally's identity and what info they hold, leading to the discovery of personalized experiences with the ally with info in question.

Description
This section details numerous potential identities of the ally with info, including theoretical explanations created by those who have not encountered such an entity.

Lakitu Bro
The most commonly accepted explanation to this dialogue, if one is to enter the mirror room, the Lakitu filming the player can be seen being reflected. They are considered an ally to the player characters, and occasionally give the player tutorials in levels such as Whomp's Fortress, leading many to believe they are the ally with info. However, they do not have any specific info within the mirror room, and follow the player to other areas, so why they'd be specified to be in the mirror room is unknown. However, in some personalized copies, they do tell the player something upon entering the mirror room, usually saying that the mirror looks fishy, hinting at the player being able to pass through it.

Power Flowers
Another common theory is that the ally with info, or rather allies, are the Power Flowers within the mirror room. When playing as Luigi, they allow the player to pass through the mirror, helping the player. In the Mario universe, several plants are sentient, so it is not a stretch to say the Power Flowers might be as well. This has led to some believing that they are the ally with info, with the info in question being allowing the player through the mirror.

Toad
In some reports, a Toad can be found behind the mirror, usually in the main room, but sometimes in the white room as well or even the Negative World. When in the Negative World, they appear inverted and have reversed or jumbled dialogue. They usually give the player a Power Star, tips on how to access hidden levels or clear missions in courses, or just story exposition on Bowser's invasion.

Allie
Allie is a unique NPC that has only been reported as the ally with info. They appear as a black silhouette with green eyes, a gray hat and a matching gray trenchcoat covering their body. Some say they have a nametag that says Allie or Ally, or even one of the names crossed out with the other name written below it. Allie usually acts the same as a Toad that qualifies as an "ally with info", but can also reportedly give the player side quests, such as talking to specific Toads in a specific order or accomplishing a task somewhere in a level. For example, this kind of side quest could require defeating every enemy or completing multiple missions in one session without actually collecting the stars. The reward is usually extra Power Stars, but some say Allie can unlock an anomalous level, an anomalous minigame, or even a new playable character.

Theorizing
It is believed that if the ally with info was not referring to the Lakitu Bro or the Power Flowers, and instead one of the anomalous examples, this dialogue is likely a remnant from the Negative World's inclusion, as it can appear behind the mirror and contain unique NPCs, including some mentioned in this page. After it was removed, the developers likely forgot to change the Toad's dialogue, leaving the ally with info as an unsolved mystery for the players of Super Mario 64 DS to speculate about.