Bigweld is the Tetartagonist of Robots. He is the head of Bigweld Industries, also owns a television show called "The Bigweld Show", and Rodney follows this show in his childhood. He has no legs, but resembles an enormous titanium sphere on which are added arms, a tuxedo-like cover, and a head.
Bigweld has two main catchphrases heard in the movie:
- "You can shine no matter what you're made of!"
- "See a need, fill a need!"
When Rodney Copperbottom was a child, Bigweld was famous and made Robots life better until Ratchet took over since it's all about money which made Bigweld an old fashion and outmode. So, years have passed, Bigweld never went outside including his own ball, enjoys setting up and knocking down dominoes, resulting in his famous alias "King of the beach".
When Rodney tried to make Bigweld to come back, he refused at first until he remembered that Rodney said that he always want to grow up like him since Rodney believed in him since he was a kid. That's when he decided to join Rodney and his friends to beat Ratchet for good.
When trying to fire Ratchet from the company, Bigweld is hit over the head with a telephone by Ratchet. Rodney is then able to save him and flee.
However, Bigweld suffers amnesia and sings songs such as "Daisy" during their escape from Ratchet, but Rodney is soon able to repair him. Later on, Rodney and his friends saved Bigweld from Ratchet and his evil mother Gasket which they won at the end by celebrating at Rodney's hometown after telling Rodney's parents that Rodney will be working as his assistant at Bigweld's. During the movie, he also have a crush on Aunt Fanny which he later dance with her at the end
- Kelsey Grammer, Ned Beatty, Robert De Niro, Bill Nighy, Christopher Walken and Robert Redford were all considered for the role of Bigweld before Brooks was cast.
- Mel Brooks' first time voice acting in a theatrically released film. Later he'd go onto voice Albert Einstein in Mr. Peabody & Sherman (2014), Vlad the Elderly Vampire in the Hotel Transylvania films, and Melephant Brooks the Toy Elephant in Toy Story 4 (2019).