Clyde Langer

Clyde Langer was a class mate of Maria Jackson and Luke Smith. He met Maria and Luke on his first day of high school. He disliked the school dinners as the food was rotten due to a Slitheen machine in the school. The next day he brought a home made chip sandwich to school where the science teacher, a Slitheen in disguise, had a negative reaction to the vinegar in the sandwich as vinegar is the Raxacoricofallapatorian's weakness. After school his science teacher unmasked and chased Maria and Clyde, Clyde sprayed deodorant to confuse the advanced sense of smell of the Raxacoricofallapatorian. After meeting Sarah Jane Smith he helped defeat the Slitheen. (SJA: Revenge of the Slitheen)

His grandmother, who knew Mrs. Randall who lived at Lavender Lawns, tipped him off that there was something strange happening there. The claimed she made were in fact true as the manager, Mrs. Gribbins, was in league with a Gorgon. (SJA: Eye of the Gorgon) He and Luke went to laser tag centre where he and Luke were telported to General Kudlak's battle station. There he met others kids who had gone missing due to winning the laser tag. He was helped to get home safely with the help of Sarah Jane. (SJA: Warriors of Kudlak)

Alternate Universe
If Donna Noble had turned right, Clyde would have gone to investigate the Royal Hope Hospital, and met Martha Jones, with Sarah Jane, Maria and Luke. Since, as it was moved to the moon, the oxygen ran out it caused every one in the hospital, including Clyde, to die of suffication. (DW: Turn Left)