On Monday I asked:

Where is this large rock located (hint: it's not the Celery Farm), what kind of rock is it, and what is its nickname?

The answers: 

The rock is at High Mountain near the entrance at the Red Traill parking lot at William Paterson.

It is a glacial erratic.

Someone named Jim nicknamed it Potato Rock. A smaller version a bit of aways down the trail is Tater Tot rock.