O'Halloran

Ensign O'Halloran was the role played by a member of Species 8472, a male Starfleet sciences division officer in the 24th century.

In 2375, the Species 8472 member who impersonated O'Halloran trained at Terrasphere 8 for infiltrating the Federation. This O'Halloran had problems in keeping his Human form and suffered three reverts in one week; had he suffered one more, he would have been kicked out of the program. 

O'Halloran O'Halloran (espèce 8472)