It could be an Orchid cactus tho the stems look a bit narrow. If so, they can grow quite big ( height and spread ) in the right conditions and have large flowers. Whatever it's ID , you would be wise to pot it separately to allow the other cactus room. You could also remove the "floppy" bits from that one, let the ends dry for a couple of days, pot in gritty soil and they may well produce new plants. Ensure you give it all round bright light if possible.
Thanks for the suggestion. I googled Orchid Cactus, and it doesn't seem right. It doesn't have the strongly serrated edges. I'm not sure I want another one. This one dwarfs the others!
Posts
Whatever it's ID , you would be wise to pot it separately to allow the other cactus room.
You could also remove the "floppy" bits from that one, let the ends dry for a couple of days, pot in gritty soil and they may well produce new plants.
Ensure you give it all round bright light if possible.
Gardening in Central Norfolk on improved gritty moraine over chalk ... free-draining.