What type of bird is this?

my cats just brought home a bird and i cant tell what it is it. its black but looks greenish when the light catches it and has small brown spots on its back put mostly to the sides and tips or feathers. its about 7 inches long and has a beak of about 1 inch to 1 and a half. i believe it might be a type of woodpecker as we have had sightings of them pecking at a tree opposite my house but have only currently seen them a few times so not had a very good look i think here maybe feeding as the tree is infested with woodworm's and there have been sightings just down the road of a woodpecker nesting so could this be a woodpecker? or if not what type of bird is it i haven't seen one before?