While not an evolution of Passimian, it is considered a counterpart of it, as it is a version exclusive like Passimian as well as being of two types that one (Normal) weak to Passimian and the other (Psychic) strong against it.
Oranguru is one of three Pokemon that are Normal/Psychic type. The other two are Girafarig and Meloetta (in Aria Forme).
Oranguru drew comparisons to Harambe upon its debut, as previously Harambe (a gorilla shot and killed at a zoo) was petitioned by fans to be commemorated as a Pokemon. However, the official Pokemon Company has denied this.