Randall

Randall is Penny's. Apart from Penny, he has another unnamed sister, and he is the only of Wyatt and Susan. He has finally appeared in season 10, but was previously only mentioned.

In "The Dumpling Paradox", Penny says that her Christy Vanderbel was  to her (Penny's) cousin while she was  her brother.

In "The Pirate Solution" (S03E04), it is revealed that he works in a and is described as a 'kind of ' and Penny told Leonard that Leonard would like her brother.

In "The Rhinitis Revelation" (S05E06), Penny asks God to make her brother stop cooking but without involving the  when Sheldon's mother decides to get them to pray at a  church.

In "The Status Quo Combustion" (S07E24), Penny wants to schedule her 12 to 18  away so her brother can attend after he gets out of.

In "The Bachelor Party Corrosion" (S09E03), Penny's father tells Penny that her mother is out with her brother celebrating one month of being sober. He had also received his 10th one-month-sober chip.

It's revealed in "The Convergence-Convergence" (S09E24) that Penny's brother had been released from prison due to overcrowding, making him eligible to attend her redo wedding ceremony with the family.

In "The Conjugal Conjecture" (S10E01), Randall comes to Pasadena with his parents to attend the re-wedding, he smiles a lot and embarrasses his mother.