Wildlife Spotting

Found in our garden in Durban on the leaves of an Epiphyllum plant.
At first sight looked like a new bud forming on the plant, until it moved!
(Must have legs that fold underneath the body).
It was partly covered with the thick white milky, sticky substance as seen in the photo.
I guess it extracts it from the Epiphyllum plant, as there was damage to the plant flesh.
It was well camouflaged, being the same colour as the plant.
It was about 1.75 to 2.25cm across, had a hard outer skin (crustacean-like exoskeleton?),
not soft bodied at all, and quite flat.
Unfortunately, I did not inspect it fully and cannot recall what it looked like underneath.
(Also had trouble trying to get a close-up photo that was in focus using my brand new
Canon camera which I had not learnt to use yet! Sorry!)