A car runs over a man's head as he lies in the road. Only the characters in the car's reactions are shown (they don't see what happened and assume it's a speed bump), but the noise is quite graphic.

Not exactly squashed but one character's head gets severely mutilated by an accident involving a utility pole and another character smashes his head on a desk repeatedly.

Oberyn Martell's head is crushed by the Mountain.

There is NO literal head squishing in the movie. Thor's head is seized and threatened to be squished, but THAT IS ALL.

Probably the goriest part of the movie. You’ll know when it’s about to happen.

There's a fair amount of decapitation which leads to heads being kicked and carried around

Does a head getting eaten count as squashed? I'd say yeah, but some my disagree.

Yeah, a bunch of walkers get their heads squished throughout the show, there are so many instances of this happening that I can't think of just one example.

Twice throughout the movie a head is squashed, one being possibly the most gory death in the franchise.

A head is run over by a lawn mower and is shown again stitched back together

In the first episode of Golden Wind Giorno uses one of his abilities to send the damage from an attack back to his attacker, Leaky Eye Luca. This causes the back of his head to cave in with an imprint of the shovel he was attacking Giorno with.

Heads explode in the game from direct gunfire and other assaults.

Roanoke

One gets ripped off, so yea

Several heads /are/ blown off by a gun, though

One character had his head bashed in by a metal ball, although I don't think there was any gore shown, only blood.

several characters are graphically shot in the head

Deputy gets his head squished by gator while being chomped on

a character gets bashed in the head with a hammer while gardening

This happens multiple times, to multiple characters, in multiple episodes, in gory detail.

If you follow the Dark Brotherhood questline, there is a head-squashing.

Someone's head is crushed with an ATM machine.

In a very gory scene, a character is murdered by having a big stone spike from the church roof pushed onto him. His head and upper torso pretty much explode.

In chapter one, a corpse is shown with their head split open. It's rather detailed and up-close.

A man gets his head slammed into a mirror, then bashed into the sink repeatedly and suffers injuries from it.

Hand man go bye bye