A simple PSA, lest your tail-sporting character look like they’re walking around with a really long poop hanging out of their pants.
The second one is actually anatomically correct. You’d have to either have a second spinal extremity, de-attach the spine from the sacrum, or somehow get rid of the entire sacrum—which is a large chunk of the pelvis and one of the last bones in the spine. It’s the bone that supports the spine and attaches it to the pelvis. Without it, you destabilize the entire skeleton. It’s that hard place nestled between our booty cheeks that always makes us uncomfortable on hard seating.
The tail would logically extend from the sacrum—that’s where the coccyx protrudes from. The tiny tail piece left over from our ancestors. That’s where the tail protrudes from on non-humans, and yeah, that makes it a “butthole tail.”
Sorry to add the commentary but I study anatomy and it’s hard to overlook stuff like this. I feel that misinformation should be stopped whenever possible.
If you think that anthro tail anatomy is cringey, check out the fun that inevitably erupts whenever you have lizard/dolphin/otter/etc characters and try to combine ‘thick lizard tail’ with ‘I don’t want to get rid of the sexy humanoid butt’.
You either end up with a banana tail that tapers to the width of a toothpick at the base, or you end up with a tail that sprouts from slightly below the shoulder blades.
Bonus round: try drawing a thick-tailed character, sitting, with the tail pointing behind them. Can you avoid the two techniques above without causing horrific spinal deformity + lower body paralysis?
This is legit an actual problem for people who want to draw human-proportioned anthros doing everyday things like
porn/sitting in chairs /porn while sitting in chairs without having to give them inhumanly wide hips or narrow legs. The most common solution I see is to draw them from the side and hope nobody realizes that that the tail would have to narrow to the width of a sheet of paper in order to squeeze between the character’s asscheeks.
For a while I tried to give my own generously-tailed anthro OCs (a dragon and an otter) more humanoid proportions so they’d match their universe’s Star-Trek-aliens motif, but after running into these kinds of issues I think I’ll stick to the animalistic bowlegged anatomy just so that they don’t look like circus freaks whenever they have to turn around.
And this is why when you do character design, knowing about the skeleton structure is important.