Flail

The creature that flails around frantically?

— Brooklyn Nine-Nine S6E3

Now he's flailing.

— Grey's Anatomy S4E6

Oh, I can see if Phil has that thing in his car that flails around like this.

— Modern Family S8E16

You come face to face with a massive monster with a gaping maw full of teeth, three huge legs, and flailing tentacles.

— The Big Bang Theory S12E16

That is an authentic flail I won at the Renaissance fair.

— How I Met Your Mother S9E19