Wikipedia
Molgula
Sea Grapes or Molgula sp. are very common, globular, individual marine tunicates roughly the size of grapes.
They are translucent with two protruding siphons. They are found subtidally, attached to slow-moving submerged objects or organisms.
In the western Atlantic Ocean, they range from the Arctic to North Carolina, to the center of the United States Eastern Seaboard.