bobblehead

bobble +‎ head

bobblehead (plural bobbleheads)

1. A collectible doll with a bobbing head.
2. (figurative) A thoughtless person.
   • 2021 February 2, Katharine Murphy, The Guardian‎:

     Muzzling Kelly also elevates a semi-professional obscurantist to the status of free speech martyr, and that invites a cacophonous pile-on from the rightwing bobble heads who screech about the left’s obsession with identity politics while shovelling identity politics at their audiences.

• bobble-head doll syndrome

• head bobble