The ex-NFL player who starved his dog to death is officially behind bars to serve his 9 month sentence ... and TMZ Sports has his mug shot.
We've learned ... 27-year-old Terrence Cody has checked in at the Baltimore County Detention Center ... a place that only has 1 star on Yelp (seriously, we checked).
Cody was a former Ravens defensive tackle -- but was cut in 2015 after he was convicted on various animal cruelty charges, including illegal possession of an alligator.
As we previously reported, prosecutors say Cody neglected his pet canary Mastiff for a month -- until the animal finally died from extreme starvation.