| 角色 | 饰演者 | 角色介绍 |
| Lt. Frank Parker (66 episodes 1998-2001) | Jonathan LaPaglia | |
| Dr. Olga Vukavitch? (58 episodes 1998-2001) | Justina Vail | |
| Nathan Ramsey? (54 episodes 1998-2001) | 尼克·西塞 | |
| Capt. Craig Donovan? (53 episodes 1998-2001) | Don Franklin | |
| Dr. Bradley Talmadge? (53 episodes 1998-2001) | Alan Scarfe | |
| Dr. John Ballard? (38 episodes 1998-2000) | Sam Whipple | |
| Dr. Isaac Mentnor? (35 episodes 1998-2001) | Norman Lloyd | |
| Andrew 'Hooter' Owsley (16 episodes 2000-2001) | Kevin Christy | |
| MIB #1 (14 episodes 1998-2000) | Charley Lang | |
| MIB #2 (13 episodes 1998-2000) | Jerome Butler | |
| CZN Reporter? (10 episodes 1999-2001) | Kevin Hayes | |
| President Robert Maxwell (9 episodes 1998-2001) | Holmes Osborne | |
| NNL Operator? (6 episodes 1998) | Stacey Stone | |
| Lt. Owens (5 episodes 1998-2000) | Le'Mark Cruise | |
| MIB #1? (5 episodes 2000-2001) | Mark Houghton | |
| Jimmy Parker (3 episodes 1998-1999) | Roland Gibbons | |
| Dr. Lola Manson? (3 episodes 1999-2000) | Ursula Brooks | |
| Basketball Kid? (3 episodes 1999-2000) | Aaron Joseph | |
| Judy? (3 episodes 2001) | 朱迪·泰勒 |
