Yaaku (also known as Mukogodo, Mogogodo, Mukoquodo, Siegu, Yaakua, Ndorobo) is a moribund Afroasiatic language of the Cushitic branch, spoken in Kenya.
It is lexicostatistically distinct, having been influenced by Maasai and perhaps also by an unknown substratum, but it shows closest resemblance with the Arboroid languages.
They adopted the pastoralist culture of the Maasai in the first half of the twentieth century, although some still keep bees.
In early 2005, Maarten Mous, Hans Stoks and Matthijs Blonk visited Doldol on the invitation of a special Yaaku committee, to determine whether there is enough knowledge of Yaaku left among the people to revive the language.
Full language revival is improbable because of the scarcity of fluent speakers, but one of the possibilities for a partial revival is to use Yaaku vocabulary in the framework of Maa grammar, a strategy that is analogous to the making of Mbugu, a mixed language of the Usambara mountains in Tanzania.