The Beta Series is the predecessor to the Alpha Series created by Gil Alexander. Standing at 6'3 tall, its already intimidating size is amplified by its main weapon: a fully upgraded gatling gun attached to its right hand in similarity to the drill of the Bouncer class Big Daddies.
Its helmet may be its most distinguishing feature, normal shaped, with an oval porthole that changes color depending on its mood. Though it is similar to its precursor, the Alpha Series, Beta Series Big Daddies have the unique ability to think, providing an enourmous tactical advantage in skirmishs or full out battles with Splicers.
This thought process also gives them the sense to use a portion of the ADAM their appointed Sister gathers from corpses throughout Rapture, and spend them on Gene Tonics and Plasmids to better protect their charges.
This however, is a double edged sword as Splicers can sense and will attack the Beta Series without their Sisters present to consume the ADAM in their blood. Thankfully for Gil, the designers saw fit to remove the Pair Bond effect from the Beta Series to prevent the grisly losses suffered in the Alphas. This was countermeasured by the presence of Plasmids in the Beta Series', however, almost rendering that point moot.