Reptoid
Reptoids were a reptilian species whose mating practices were well known to Beckett Mariner.

According to Mariner, after a female reptoid found its male partner, it would "jab [him] with her reptoid tail" and "implant her reptoid spawn" into the male.

In 2380, Mariner suspected, with 99.8% certainty, that Brad Boimler's girlfriend, Barb Brinson, was a reptoid, on account of Brinson's admission that Boimler "looked sexy" and that there was "no way she's Human. That's her tell." 

Later Mariner, fearing for Boimler, ran up to the couple as they kissed, and yelled "Watch out for the tail!" as she pulled down Brinson's pants. After Mariner's suspicions were proved wrong, she stating out loud, "Where's-where's the tail? Reptoids implant with a barbed tail. They... Her name is Barb!" ()

Species