Twenty-Fifth Bam (Korean: 스물다섯번째 밤; RR: Seumul-daseot-banjjae Bam; literal translation: Twenty-fifth Night) is the protagonist of Tower of God. Bam is the latest Irregular to enter the Tower, but because of his young age and naiveté, his abilities don't resemble those that previous Irregulars are known for.

In the story, Bam enters The Tower in search of his best friend Rachel, the only person who visited him and cared for him in the years of isolation that he spent in a cave underneath the Tower. After entering the Tower, he is told that all the answers that he seeks will be answered if he climbs the tower, though he is immediately presented with a seemingly impossible and deadly test. Bam succeeds, and is allowed to move onto the second floor, where all would-be Regulars start their ascension. Throughout the webtoon, Bam makes several friends among the candidates, and together they pass the many tests of the floor.