The designer of Tails, Yasushi Yamaguchi (A.K.A Judy Totoya), took to Twitter recently to share some insights into the creation and design of Sonic's sidekick, to coincide with Sonic the Hedgehog 2's 30th anniversary.
In the thread (spotted by fansite Sonic Stadium), Yamaguchi shared that it was Yuji Naka's idea to make the character less of a rival and more of a beginner character that anyone could pick up. The impetus for this was so that he could play the game with his younger sister.
According to Totoya, Naka wanted the designer to create a cute character similar to Urusei Yatsura's kitsune from the anime of the same name. Though, as Totoya reveals, his first take on the design wasn't impactful enough, so he decided to add two tails to the character instead of one. He credits Phantasy Star's Myau as the inspiration for this addition.
In the thread, Totoya also states that, because Sonic the Hedgehog was a smash hit in the US, the team at Sega wanted to create this new character as a way to appeal to Japanese audiences. It designed the character's backstory and colour to directly contrast with Sonic's, with the relationship between the two also being modeled after Dragonball's Piccolo and child Gohan.
Totoya then ends the thread, revealing that Tails' name 'Miles Prower' was indeed a pun on miles-per-hour and that his surname was a combination of the phrase 'per hour' and 'power'. It's a neat insight into a classic game, with some details we've never heard before, even as followers of Sega's history.