Subject Delta is a prototype from the initial line of Big Daddies, known as the Alpha Series. Delta was the first Bid Daddy to be successfully bonded to a Little Sister, but in a traumatic event he was violently separated from her. After ten long years, Subject Delta has mysteriously reappeared and found himself with a unique trait among Big Daddies: free will. The Alpha Series is more streamlined and agile than later Big Daddy models, making Subject Delta one of the most powerful forces in Rapture. Wielding a hand-mounted drill and an extensive armory, Subject Delta has embarked on a single-minded quest to find his former Little Sister and be reunited with her.

Subject Delta (formerly the Big Daddy player) is highly detailed and over 7" tall, has removable hoses and backpack tanks, an interchangeable drill arm, and ball joints at the shoulders, elbows, wrists, waist, hips, knees and ankles.

The following users have Subject Delta in their collection:

The following users have Subject Delta on their wishlist: