Otis is 22 pounds, 17 inches tall and according to foster does not bark.
O. K. so within expected parameters for a Basenji. Only DNA testing will tell you for sure, but certainly big for a Chihuahua. It would be interesting to know more about his mannerisms.
Otis looks extremely cute and loveable. Siz and weight are within Basenji Parameters. The pose that others post are Basenji like are a standard play bow exhibited by dogs of all varieties so not really indicative. You're naturally curious but when it comes down to it I'm sure DNA results will not make an iota of difference in your love for Otis..