Someone online mentioned an odd variety of tomatoes today:

Black Pearl Tomato
Two different flavors in one tomato!
NEW Burpee Exclusive.
A true treasure, 'Black Pearl' is two different flavors in one cherry tomato. Enjoy right off the vine, but be sure to put a big bowlful in the refrigerator for a special treat. When chilled, 'Black Pearl' has a unique, extra sweet, 'Concord' grape flavor.

Is it a grape or a tomato! Make up your mind!