Pokémon developer Game Freak once held a Pokémon popularity poll among its staff members before the release of Pokémon Red & Green, and a surprising Pokémon won. Pokémon Red & Green spent a lot of time in development and Game Freak revised the initial roster of Pokémon on a number of different occasions, before deciding on the initial 151 Pokémon.
In recent years, the initial designs of the original Pokémon have been revealed in different media. The original Capsule Monsters pitch document was released in Famitsu magazine, which included some of the earliest concepts for the series, as well as some Sony-brand Pokémon trading machines. A manga depicting the early life of Pokémon creator Satoshi Tajiri showed some early designs for the original Pokémon, from the period when Pokémon Red & Green had entered production. The biggest insight into the design of Pokémon Red & Green happened when an early build of the games leaked online, showing one of the earliest working versions of the Kanto region.
Game Freak holds a massive amount of sway over the Pokémon franchise, as it has developed nearly all of the mainline games in the series, and is one-third owner of The Pokémon Company. In the early days of Pokémon Red & Green, the roster of Pokémon was worked on by different staff members, and they once voted on who the most popular Pokémon was among them.
Exeggutor Is An Eggscelent Pokemon
Fans might expect Pikachu to have won the vote, considering it became the mascot of the franchise. Clefairy is another strong contender, as it was also under consideration to be the mascot. Neither of these Pokémon won, nor did Charizard, Mewtwo, Dragonite, Eevee, or any of the other super popular Pokémon from Gen 1. According to Bulbapedia, comments made by Shigeki Morimoto in Pokémon Sun & Moon, as well as the Satoshi Tajiri Pokémon manga, confirm that Exeggutor was the most popular Pokémon among the staff. Chansey and Clefairy also placed high in the poll, making it even more surprising that Clefairy never had a bigger role in the franchise, outside of a single Japan-exclusive manga.
It's not hard to see why Exeggutor won, as it has a design that's both adorable and goofy. Exeguttor's popularity also paid off with how strong it was in Pokémon Red & Blue, as Grass/Psychic-type was a powerful combination in Gen 1. Exeggutor is also part of Blue's team at the end of the game unless the player chose Squirtle as their starter. The might of Exeggutor waned over the years, but Exeggutor did receive the best Alolan form by far, as the giant palm tree version of the Pokémon was one of the highlights of Pokémon Sun & Moon.
Source: Bulbapedia