How are y'all getting these mushrooms' heads to stay up!?

I'm making my not-so-little guy to join the army but even though I've added more stuffing and tightened his head on well it just won't stay up!! He breaks his neck every time I move him. Some advice is appreciated! Or else Porcini is going to be looking at the sky forever...

I'm making my not-so-little guy to join the army but even though I've added more stuffing and tightened his head on well it just won't stay up!! He breaks his neck every time I move him. Some advice is appreciated! Or else Porcini is going to be looking at the sky forever...