Looks like Trametes spp. AKA “Turkey tails”, they look a bit too thick to be T. Versicolor (the turkey tail) but they could be a different one.

To get a better id, could you please post a close up of the underside? Also, run your finger over the pores on the bottom to see if they change colors when bruised (they probably won’t if I’m right about it being Trametes but worth checking).

Trametes usually grow on dead wood rather than parasitizing live wood so your tree is probably in rough shape.