Gooigi, Luigi’s gelatinous doppelganger, is prominently featured in Nintendo’s Luigi’s Mansion 3. Since Gooigi made an appearance in Luigi’s Mansion 3DS, fans have pieced together theories regarding his origin and role in the Mario universe.
Speculations range in feasibility, but very few approximate the truth. Everything from multiplayer mansion to science experiment gone wrong has been suggested. The most popular justification for Gooigi’s appearance in the 3DS version of the game is simple. Once it became clear that Luigi’s greener friend was to be heavily involved in Luigi’s Mansion 3, a singular theory formed: Luigi’s Mansion 3DS brought Gooigi into the fold to tease the upcoming gameplay of Luigi’s Mansion 3. While this is entirely plausible, it’s only a small slice of the full story.
The real reason Gooigi made a cameo in Luigi’s Mansion 3DS is much, much stranger.
The story was solidified by Nintendo as part of Professor E. Gadd’s Journal. The journal was posted on Nintendo’s website and includes a never-before-seen look into the mind of Professor E. Gadd himself.
There’s a lot to take in, but the most important finding is the detailed account of Professor E. Gadd’s experiments with Gooigi. Within the journal’s pages, the professor reveals that Gooigi’s purpose in the 3DS adaptation of the original GameCube game is a lot more than a simple teaser of Luigi’s Mansion 3.
The journal confirms that Professor E. Gadd was actually sending Gooigi back in time to conduct research for Luigi’s Mansion 3 as part of his documentation of the evolution of Gooigi. From the professor’s “accidental discovery” of goo to the final stage of “Gooigi’s completion,” nothing is left out.
Toward the end of the journal, E. Gadd even highlights his ability to transfer his consciousness between his own body and that of Gooigi’s.
“I attached a sensor to the part of the Poltergust that would touch the user’s back, and then tested the system on the only available subject: myself,” he writes. “And everything went as planned! Heh Heh Heh! By basically becoming Gooigi, I was now able to control his body as if it was my very own!”