How odd is that?

I can't give an i.d. but I think it is a fungus of some sort, if you look there is a small open 'cup' that this has been produced from. After an extensive Google search, and looking at the pic. the right way up! I think it could be an Anemone fungus that is going over... But the person asking the question is, apparently, in the UK and this is a fungi of Oz., NZ... so I am at a loss!

https://en.wikipedia.org/wiki/Aseroe_rubra

has it been broken off the structure to the right of it. It is a fungus definitely .

I think it fell of rather than was broken off as it went over, when the image is the correct way up the 'cup' is below the fruiting body...

It's a stinkhorn fungus, Clathrus archeri. Although not indigenous to the UK and Europe, it was introduced here and does crop up occasionally, and yes, the top has broken off the base. Info and image here, you'll need to copy and paste into your browser, or just google Clathrus archeri

https://en.m.wikipedia.org/wiki/Clathrus_archeri

This is Devil's Fingers or Octopus Stinkhorn fungi. It also has a putrid odor & slime containing its spores. It's indigenous to Australia.

Aka stinky squid stinkhorn fungus. Last year we had quite a few of the single fingered variety of stinkhorn and they were quite a curiosity for those who walk their dogs early in the morning to see and this year it is puffballs. It seems the predominance of fungus types changes from year to year. Best time for this type of viewing is early morning before children get outside of the house, once they are out these things get smashed to smithereens by them.

Wow, never seen one of those before! Its very different from our native stinkorn isn't it? Whereabouts in the country are you Mattbest?(just wondering if there's any chance of seeing one...)

Very interesting. I suppose they have been introduced on imported plants. Would like to see one too.

That would be my guess

It is native to Australia but is now found in warmer areas of Europe, habitat is gardens and leaf litter.

Probably widely spread from spores contained in agricultural imports of various kinds.