And I can claim I'm the Queen Mum, but it's not true.
He is definitely huge, but maybe 8.5. I'm pretty sure he's got some Apple magic working there, but not sure.
These pics almost certainly have been touched by an angel. The first picture, in particular, is disproportionate to the second one, and the vascularity in the first pic is different (it’s been smoothed out, suggesting a lasso of a section).
The second pic certainly isn’t 10” — 8.5, maybe 8.75.
That's DynamikDuoXXX, been discussed here before a few times and he even submitted his own attempt. He's absolutely massive, 8.75"-9" based on my own estimates since he has a slight curve that he doesn't show often, but nothing over that. Most of his pics and videos are from that above angle.
I'm thinking 8.75 inches MAX. But regardless the guy is massive length wise. No way anything over 9 inches though and certainly not 10 inches.
He has measured pics IIRC. Side measurements that place him in the mid-upper 9 range IIRC so mid to upper 8 range if measured properly.