What's the Name of That Book??? discussion

My boyfriend and his family are looking for a children's book they used to read when he was in hospital as a child.

Apparently it was about some creatures called snugglies who get in beds and on sofas. Eventually people find they can't get into bed or sit down as the snugglies have taken all the space. Apparently it involves a cinema as well.

They'd be so happy if I found it but Google keeps failing us. Can anyone help?

Snuggly by Jim Slater seems likely?

This is it! Thankyou!!!!