Sciurus carolinensis, known in North America as the eastern grey (they write "gray") squirrel.
It was introduced into Britain in the last quarter of C19th.
Alas, it has generally replaced the native red squirrel (Sciurus vulgaris).
we have a job for you, grey squirrel : you are to travel to exotic distant lands, meet exciting squirrels (excited people) and kill the reds
We know they is habouring mass acorns and they pose a threat,
we read it in Mad magazine