It was a pretty good marketing idea - stick googly eyes on some fake fur and sell it as a toy. These two are even cheaper - with feet and faces made of cardboard.
These ones with 'beaks' are reminiscent of Tivvy, the TV Times mascot, who in turn is reminiscent of a Finnish Fauni troll. I bet you didn't know there were so many varieties.
In a mood of vigorous enquiry, I decided to throroughly investigate the origin of gonks. Well, I googled it, anyway. Turns out that, officially, these are not Gonks at all, but Glooks. Gonks were a different sort of toy, like Humpty Dumpty with a Beatle cut. And, rather marvellously, there was a film called 'Gonks Go Beat' made in 1965.
You can even buy it on Amazon. I'm a little bit tempted now...