As a child, Birdo and its siblings were abducted by Wart. Birdo then worked for Wart as a soldier and officer, becoming known as the greatest warrior in Shyguyland and fighting Mario. When Shyguyland suffered an economic crash, however, Birdo went to live in Palermo, Sicily. When Wart discovered this, he decided to retaliate by attacking Yoshi Island, but this ended in failure when Evil Link invaded Shyguyland and killed Wart. Birdo also befriended Yoshi, but was then conscripted into Evil Link's regime and moved to Hyrule City, Gomalan, where it married Yoshi. Birdo began to fight for Link's army and became the top soldier until 2036. When younger Link killed older Link in 2040, Birdo decided to make herself and Yoshi the leaders of Hyrule. However, she faced opposition from many Hylians who wanted the Harkinian rulers back, so she allowed Harry Harkinian to return to Hyrule. Birdo legalized forms in Hyrule in 2080 and continued to lead until it was killed in 2102. This started a brief period of anarchy, and Weegee revived Birdo as a cyborg in 2105. Birdo returned to power with an army of Gay Luigi clones and defeated Leopold Slikk II, then ruled for years and arranged for the establishment of a democracy in 2146. Birdo committed suicide in 2205.
One of the main things about Birdo is nobody knows what its gender is. Some claim Birdo to be a male cross-dresser, while others confirm Birdo to be female (which would make sense). After about a month, Birdo was officially declared a woman, much to King Harkinian's disappointment.