Having the quill feathers of the tail somewhat rigid.(adjective)
Gnu Collaboartive International Dictionary of English: licensed under The Code Project Open License (CPOL)
Use "stiff-tailed" in a sentence
"She stood stiff-legged and stiff-tailed, her white fur standing straight up on her back."
"'Did you think the book would be famous when he read it to you in 1834, as you say?' asked the Professor, beaming at him in a way that would have melted the heart of the stiff-tailed lion of the Northumberlands, if he'd possessed such an organ."
"On a subsequent visit we found that she’d met a friend and had a fleet of stiff-tailed babies."