As far as the Axl sprite goes, it's not made by Capcom, that's for sure. If anything is a giant tip-off, it's the hair. It's way too smooth and for that matter, light for that tone of color for Capcom's work. I wouldn't go so far as to say it's a flat out edit of Zero but probably heavily referenced. Another thing is that I don't think Capcom would have put that yellow thing-a-mabobby under Axl's chest gem. It's too thin and too small of a detail to matter or bother with in sheeting a sprite officially.
If anything, they would have taken that out. The only reason Zero has the yellow line at the top of his torso is to seperate his head from the chest, (If he didn't it would look like his head and chest are the same) it's exactly the same as when Nintendo made Mario's sprite the first time. The only reason he ended up with a mustache is because they wanted to seperate his nose from his chin.
As far as BBD, Zan or Oakie making it, I'm 99.99% sure that it wasn't Oakie. He's more or less sick of peoples comments on Apirl fools jokes and the lack of people treating them like jokes, and something to linch others for. Zan is a possibility, but he just said didn't do it. So, I'll take'em for his word, and BBD well, you'd think he's gotten tired of MM mock-ups, but I've been wrong before.
And I know I had nothing to do with it. It was the Sloth I tells'ya!
It could be anyone on this forum who knows how to sprite and has Mspaint. But If it is a joke, let's just sitback, relax and blame it on Canada and not be overly serious.