Penguin-shaped caterpillar ?
This is a tent caterpillar, commonly found throughout Baltimore, Maryland, on the East Coast of the United States.
This type of caterpillar usually lives on cherry and apple trees, thrives in the spring, and after 5 months the worm turns into a moth.
When the young tent caterpillars hatch, they are black, then a white stripe appears along their back with a special pattern, like this caterpillar which looks like a penguin.