Louie's notes

Like Captain Olimar, Louie takes notes too, but his notes are about how to cook enemies. While Captain Olimar's notes would be useful to a scientist or biologist, Louie's would be useful to a chef (However, probably not to a human chef, as many of the recipes seem disgusting to us). Interestingly, Louie references ingredients found on Earth (cultivated in oxygen). These ingredients could not possibly be known by Louie, as Hocotate has a severely different climate. This is most likely because Hocotatian plants often have a similar appearance to those found on Earth so Louie uses the names he is familiar with for a completely different plant.

Louie's Notes, like the Sales Pitches for treasures, are not shown in the beginning of the game and are unlocked by defeating the Titan Dweevil.

Example

Titan Dweevil

"Eaten raw, this predator's luxurious legs are bold and full flavored. What a satisfying crunch!"

Musings of a Sidekick

In addition, on June 18, 2009 on Nintendo's site, an article titled "Louie's Notes: Musings of a Sidekick" was revealed. It was essentially a humorous commentary written by Louie, comparing himself and Olimar to other famous Nintendo duos (Mario and Luigi, DK and Diddy Kong, Link and Navi, Pikachu and Pokemon Trainer) likely used to promote the New Play Control edition of Pikmin 2.