They did it, they only went and did it. Although the Pokemon games are known for stuffing themselves with Easter eggs, the recent release of Pokemon Legends: Arceus has the ultimate throwback that's been some 18 years in the making. 

Pokemon Legends: Arceus has some deep cuts to the franchise's past, with Commander Kamado being the ancestor of Diamond and Pearl's Professor Rowan, an active Stark Mountain volcano, and speculation Galaxy Team will eventually evolve into the villainous Team Galactic. However, another sneaky Easter egg stands out more than most.

What Is The FireRed And Leaf Green Easter Egg?

Over on YouTube, the channel Viz explains how Arecus' Pokedex entry for Raichu ties back to a throwaway line from 2004's FireRed and LeafGreen. Here, Raichu's description reads: "It can reach even 100,000 volts. Careless contact can cause even an Indian elephant to faint." Jump forward to Arceus and it now reads: "It can discharge bursts of electricity exceeding 100,000 volts— a single strike with that amount of power would incapacitate one of the Copperajah of my homeland."

The Pokemon masters among you will know Cooperajah wasn't introduced until 2019's Sword and Shield, making Raichu's Pokedex entry come full-circle thanks to the fact Arceus is set at the very start of the franchise timeline. Unsurprisingly, Arceus players were suitably impressed by this subtle nod to yesteryear. 

One gamer wrote: "What I love is they had to wait to update that info since the only other elephant for awhile was Phanpy line which.. is immune to electric." Another said, "Imagine the sole reason for Copperajah's creation was to explain that Dex entry," while a third concluded, "This is when someone puts actual effort on the little details of a game. Amazing, love to see it."

Wait... There's Another Pikachu Easter Egg

If you weren't satisfied with one Easter egg relating to Raichu and Pikachu, how about another? On Reddit, u/PricklyBob noted that Arceus confirmed a long-held theory about the adorable electric 'mon. 

Pachirisu's Pokedex entry says, "A species related to the Pikachu line," which means all those Pokemon that look like the franchise mascot are directly related to the species. Fans of the series have often assumed that certain Pokemon look like Pikachu clones because of the OG's popularity and thus helping with shifting merch, however, this Pokedex entry for Pachirisu suggests otherwise.

Whether this is evidence of The Pokemon Company's meticulous world-building or simple retconning while probably never be known. Still, it's nice that they've at least considered all the permutations during their marketing assault.