An animal puffing up its body as a defense mechanism in a threatening situation in order to appear larger in size, to signal defensive aggression towards the enemy. In mammals, this is usually done alongside a bent back.
Often accompanied by hissing. Though unlike hissing which is an offensive move almost always shown as a form of threat or anger, puffing up can be seen on other occasions such as fear or shock.
Pixiv
Twitter
Bluesky
Weibo
Lofter
Tumblr
