Debbie Wolowitz

The mother of Howard Wolowitz , who is also the mother-in-law of Bernadette Rostenkowski-Wolowitz. As a joke in the series, she has never physically appeared on-screen (except for two episodes that barely show any of her detail) -- but her presence is made clear by her loud and obnoxious voice.

Physical Description
Mrs. Wolowitz is the only unseen character in the show; she hardly ever appears on-screen, but her voice is often heard while she is in a location in the scene that the viewer cannot witness (i.e. in the dressing room in a department store while the camera never focuses on the dressing room). The most prevalent form of her appearing is when she calls Howard in a loud voice while Howard is in his room and she is in another part of the house. Since she almost never appears, our knowledge of her is limited to the physical descriptions of her given by the characters on the show.

Verbal descriptions depict her as an immensely overweight woman with a mustache, as she takes water aerobics classes for overweight people. She once mentioned that she had been a beautiful woman to whom the boys used to flock and give candy. Clues to her appearance have been provided in several episodes, including the episode "The Hot Troll Deviation", in which she states that she was spilling out of her shrunken girdle like "the Pillsbury Doughboy". In the episode "The Hawking Excitation", Sheldon states that he strained his wrist while helping Mrs. Wolowitz lift her bosom when he takes her dress shopping, further confirming her excessive weight. Another mention of her size was in the episode "The Engagement Reaction", in which Penny doubts Howard's ability when he stated that he lifted his mother up to take her to the hospital. Penny's doubt was founded in the belief that Mrs. Wolowitz's own legs were barely able to lift her up, never mind her petitely built son.

In the flashback episode "The Staircase Implementation", Mrs. Wolowitz had a younger, louder and more masculine voice, that makes Leonard mistake her for Howard's father. Howard promptly points out that with any more facial hair, she could pass off as his dad.

In "The Spoiler Alert Segmentation", Mrs. Wolowitz is finally seen in comprehensive detail; the camera scene is that of Raj siting in the dining room whilst the door to the kitchen is visible in the background. Howard's mother is seen walking across the kitchen (visible by the kitchen door) twice in this scene, but both appearances deliberately fail to show her face. More so, the closing scene in the episode shows Mrs. Wolowitz's hands pulling Raj back in. Although much of Mrs. Wolowitz's appearance (namely her face) is still left to mystery, this episode confirms that she is immensely overweight. Comically, the background audience gasps slightly the first time she is seen walking across the kitchen. Also, in the tag scene when Mrs. Wolowitz catches Raj trying to sneak out, her hands and part of her hair can be seen.

History in the series
Mrs. Wolowitz was abandoned by Howard's father when her son was 11, before then, they just stayed together in silence without saying a word or being drunk all the time, as mentioned in "The Grasshopper Experiment". Howard lived with her until his marriage and often referred to her as "living with him", even though it's obvious that she's the responsible one when it comes to living standards.

Mrs. Wolowitz often talks to her son like he is still a child and isn't aware of his adult accomplishments, filling the cliché of a Jewish mother, referring to his colleagues and friends as "playmates" or "little friends", and referring to his work at the university as "going to school".

Howard often makes references to his mother as being a "crazy old lady", but deep down, he is still attached to his mother, being such a mama's boy. The attachment is primordial, as he relies on her to wash his clothes, as well as alimentary needs. Howard has no problems with this, as he gets to keep eating his old-time favorite childhood foods.

Her cooking skills are mixed. She is able to cook a brisket to the point where it just melts in the mouth. But she takes things beyond edible on Thanksgiving with her "tur-briske-fil" (which is turkey stuffed with brisket stuffed with gefilte fish, like a turducken). Also, her meatloaf lacks breadcrumbs and has been used over the generations to test diverse plumbing systems, including Howard's famous "space toilet".

Howard's mother is rigorously Jewish. She evaluates Howard's partner choices vociferously (like insisting that the latter be Jewish too), but she does not take kindly to strangers taking control inside her house (as in her argument with Howard's partner, Christy in "The Dumpling Paradox"). Despite this, she stated in "The Engagement Reaction" that she likes Bernadette, even though Bernadette is not Jewish, considering she went to Catholic School. Bernadette has developed some of the same personality quirks as Howard's mother including shouting like her when upset and mothering her husband.

As of "The Habitation Configuration", Howard no longer lives in his mother's house, having moved out to live with Bernadette as husband and wife; however, he and Bernadette continue to sleep over there from time to time to give her company and remind her that she is not alone.

Communication with other characters
Mrs. Wolowitz usually shouts at whoever she is talking to, but on occasions, has been heard to speak in a softer tone. This is particularly true in the episode "The Hawking Excitation" when Sheldon takes her shopping for a dress and she asks him to "hold" her after Sheldon makes a comment about her inability to fit into a dress. Whenever she speaks, she is usually heard either shouting from another room, off-screen, or over the phone.

Trivia

 * She regularly goes to the gym and eats Oreos while in baths.
 * She is extremely good at figuring out the answers with only sparse clues on the gameshow Wheel of Fortune.
 * Carol Ann Susi has said that Chuck Lorre has decided to never show Mrs. Wolowitz onscreen. However, viewers can see her from the side and see her arms and hair in "The Spoiler Alert Segmentation"; her face has still never been shown.
 * A photo of her face can be seen in some episodes, having a strong resemblance to her voice actor Carol Ann Susi except with thick glasses and curly hair. An episode where this can be seen is the "Engagement Reaction"
 * In 2007, she had a low pitched voice.
 * She was defenitely cameo seen in 2008 and 2011-2013.
 * She last appeared in 2013.

Sra. Wolowitz