Just interested to know what was going on here :)
WizardCat is starting to adventure outside our garden and next door have two cats who used to be in our garden quite a bit, but less so in the last couple of months as WizardCat has been allowed out regularly.
She just crossed over into their garden and the one sat stock still paws all bunched up underneath her, ears back and just hissed.
Wizard Cat stopped, stayed stood still for a moment, then carried on approaching, then at one point just lay down as if totally relaxed, just the tip of her tail flicking.
Neighbours cat looked away first, and WizardCat trotted further up their garden, NC followed, and then resumed the sat/hissing position, so WizardCat just sat and cleaned one of her paws, then laid down and rolled over for a second before getting up and coming back down the yard to me.
NC is quite old, and has no tail, so i couldn't tell if she was being aggressive or worried by my cat, and i only ever know the 'belly up' position as being 'i'm not worried by you' when she does it to me.