Iizuka says Shadow the Hedgehog wasn't inspired by Vegeta, but fans have receipts that say otherwise

pcgamer.com:

Sega might've declared 2024 the Year of Shadow, but Shadow the Hedgehog has been enjoying the adoration of preteens entering their edgy red-and-black phase since he first declared himself the ultimate lifeform back in 2001. And who could blame them? Shadow's like the Platonic ideal of the hero's dark mirror archetype: He's grumpy, he's a reluctant hero, he's constantly proclaiming his superiority, he's got hair spikes with an arrogant upward sweep where the carefree locks of his lighthearted counterpart might droop downwards. Actually, now that I think about it, that sounds a hell of a lot like a certain prince of all space warriors I know… 

Toe to tip, that's a Vegeta—as long as you're not counting that brief period where Shadow had all those guns. I'm certainly not the first one who's noticed the similarities. Do a quick google, and you'll find that fans have been arguing about whether Vegeta inspired Shadow about as long as they've been debating whether Super Saiyan Goku inspired Super Sonic (probably, though apocrypha claims Toriyama never complained about it). But while it might seem obvious to you and me that Shadow's got some Vegeta in him, Sonic Team director Takashi Iizuka says otherwise.

Over the weekend at Anime Expo 2024, Sega held a panel to promote Sonic x Shadow Generations, during which Iizuka was asked about the inspirations that informed Shadow's design and character during the development of Sonic Adventure 2. Answering via translator, Iizuka said Shadow's role as a dark rival to Sonic was influenced by '90s American antiheroes, citing Spawn in particular, which would account for some of the general red-and-black edginess. However, panel host Zeno Robinson said he'd asked Iizuka about the long-held assumption that Shadow was inspired by Vegeta, which Iizuka had denied. Iizuka reiterated that denial for the crowd, correcting the record by emphatically shaking his head. Sonic Team, it seems, is a no-Vegeta zone.

Unless, of course, you look at Sega's