Bev "wears the pants" in the family; she demonstrates a loud, domineering manner and she keeps her husband Ed in line. Despite all these personality traits, though, she has shown that she loves her husband very much. Beneath her ugly exterior and grating voice, she is a closet party animal (even going so far as to spy on her neighbors when Heffer threw a nudist party in Rocko's backyard). Unlike her husband, Bev is much more kind and friendly, and actually likes Rocko, Heffer, Filburt, and Spunky. Bev has invited Rocko to her house on some occasions. In the Leap Frogs episode she tries and fails to seduce Rocko, but by the episode's end Rocko is somewhat responsible for rekindling the romance in the Bigheads' relationship. Bev eventually adopts Earl in Frog's Best Friend.
Bev has orange hair, blue lips and green skin, the latter two just like her husband, Ed. Mrs. Bighead is mostly green. She has orange hair and white eyes with black pupils. She wears a pink shirt, a pearl necklace, and blue pants and white high heels.
Joe Murray, the creator of Rocko's Modern Life, said that he based the Bigheads off of a group of neighbors who lived next door to Murray during his childhood. Murray described the neighbors as grumpy. The general concept involving characters with large heads originated from a comic, written by Murray, named "Rizzo the Art Director."