I ALSO THOUGHT OF THE IXI RAIDER WHEN I SAW THIS ANSWER. Genuinely I don't think there's ever been a case of 'Neopets character that looks like a member of a species of Neopet but actually isn't' outside of cases like shapeshifting entities or other magical shenanigans. I guess there's Baby Blu petpets having heads that look like Blumaroo heads, but their description has always said they were named for the resemblance - no retcons or ignoring/overlooking the canon.
I didn't think about the implications with the 'not being able to speak' part... yeah that's. A bit unfortunate, oof.
#they took him being in a cave in the haunted woods form the card but ignored the part that said he was a lupe explicitly
And to this - I discovered this on my own after making this post but yeah the site has previously specifically called him a Lupe (in the stamp item descriptions though, not the card. But the point still stands.)
Honestly I think it's a tossup whether they knew about and then deliberately chose to ignore the 'Lupe' part of these descriptions for??? contrived story reasons??? that absolutely REQUIRED a three-headed petpet, or if they didn't know about this at all and they simply got lucky that they set him in the Haunted Woods in the plot (he's already very Haunted Woods-coded, so it's not a stretch). Again ignoring that even without the stamp descriptions he is very obviously supposed to be an Unusual Lupe the way the Ixi Raider is an Unusual Ixi.
For real I would've taken a last-minute new Luperus Petpet over this 'clearly trying and utterly failing to cover their asses' answer 😔