Felix Kawalski, played by Harry Landis, is a Jewish-Polish immigrant who sets up a barbershop in Walford. A survivor of the Holocaust, Felix has spent his life searching for his family to no avail. He assumes they had all perished in the Nazi concentration camps, so he is thrilled when he finally makes contact with his surviving sister. Felix is first seen in November 1995 when he moves to Walford to open a barber shop. He is interested in brass band music, and when he notices Sonia Jackson attempting to play the trumpet he tries to offer her the benefit of his wisdom. However, Sonia takes his kind gesture the wrong way and tells her stepfather Alan. Thinking that Felix is a paedophile, Alan immediately warns him to stay away from Sonia. Intimidated, Felix agrees. Rumours about Felix begin to spread around Walford, leading Sonia and her friend Clare Tyler to think that he had murdered his wife, cut her to pieces and buried her in the basement of his shop. They are terrified of him, even more so when Clare enters the shop on a dare and notices that he has a cut throat razor. Clare runs away when Felix refuses to tell her what is in his basement, and she immediately assumes his dead wife must have been down there. She, Sonia and Janine Butcher steal Felix's keys and sneak into the dark basement where Clare trips and knocks herself out. Panicking, Sonia and Janine run to The Queen Victoria public house and tell Clare's stepfather Nigel Bates that she has been kidnapped. Nigel, Grant and Phil Mitchell, find Felix unbuttoning Clare's clothing and immediately suspect the worst. Grant attacks Felix and only stops when Clare tells that him Felix is merely taking care of her, following her fall. As she looks around the cellar, she discovers that all Felix has to hide is a vast collection of butterflies.
The residents all apologise to Felix the next day, and they learn the story behind Felix's collection of butterflies. They learn that Felix is a Polish Jew who had been living in Kraków during World War II when Germany invaded and most Jewish residents were placed in Nazi concentration camps. Felix's father refused to flee Poland, as he would not leave his precious collection of butterflies behind. When the Nazis came to arrest his family, he and his sister hid, but he sneezed, revealing their hiding place. His sister was found but Felix escaped with a small box of butterflies. He travelled from Poland to England, where he was taken in by his uncle. He believed that the rest of his family had perished, and blamed himself for his sister's death. He continued to collect butterflies in his father's honour ever since. Felix befriends the other senior residents of Walford, Jules Tavernier, Ethel Skinner, Blossom Jackson and Nellie Ellis. He and Jules often play chess together in The Queen Victoria pub. Felix is left furious during a chess tournament when Jules keels over while asleep, scattering the chess pieces in the process. Even though Felix does not know where his family are or even if they are still alive, he has spent his life trying to find them. He eventually discovers that his sister has survived and she is living in Israel. After making contact with her, he decides to leave Walford to live there with her. He later returns for a brief visit in May 1997 to tie up some loose ends. On his return, he asks Blossom Jackson to go on holiday to Israel with him, and they depart that month. The hint of romance between Felix and Blossom remains just that, and Blossom returns to England. When Blossom returns for her great grandson Billie's funeral in October 2010, she reveals she and Felix had reconciled but he had died of an illness five years previously.