There I was sitting next to the pond tidying up the Marsh Marigold and a frog leapt out at me and bounced off my sholder and onto the slate slabs behind the pond.
As it was hot, and he was in the sun, I managed to grab him and put him back to the water, and spotted another one clinging to a pot. .
Further plant tidying revealed that there are at least 4 of them, saw 3 together and they were bigger than the Ninja frog which attacked me.