Robert Lawrence Horne is an American semi-retired professional wrestler who is most famous for his time in the World Wrestling Federation from 1993 to 1996 under the ring name Mo (later Sir Mo), where he held the WWF World Tag Team Championship with Mabel as "Men on a Mission". After leaving the WWF Mo returned to Memphis and the USWA where he became a part of the original Nation of Domination, the stable that was a forerunner to the more famous stable in the WWF. Mo became "Sir Mohammad", using a black supremacist gimmick. The USWA version of the N.O.D. was led by PG-13 J.C. Ice & Wolfie D) and also included Kareem Olajuwon (Reggie B. Fine), Akeem Muhamad (Big Black Dog), Elijah (the Spellbinder), Shaquille Ali (Tracy Smothers), Randy X, and Queen Moishe (Jacqueline). When Faarooq started the Nation of Domination in WWE, the USWA version of the group was disbanded.

Horne would remain in the Memphis region wrestling mainly as Rob Harlem, competing under that name in the USWA, its successor “Memphis Pro Wrestling”, and Randy Hales’ “Power Pro Wrestling”. While in PPW, Horne teamed up with “Deon Harlem” to form the tag team “The Regulators”. The team beat Derrick King in a Handicap match to win the PPW Tag Team Title, which they held when the promotion closed down in April 2001.

In 1997, Horne would start his own promotion “Southern Extreme Wrestling” which he both booked and wrestled for. Horne’s “Southern Extreme Wrestling” is not affiliated with the "Southern Extreme Wrestling Promotions" organization that operates today.

In 2003, Bobby Horne added yet another gimmick to his long list of gimmicks. On December 30, Mabel was at ringside commentating when manager Paul Wylde came out and introduced the “Bahamian Heavyweight Champion” "Marly Pride". Wylde started making comments that Mabel was the fattest whale which Mabel took exception to. When the big man entered the ring, Marley Pride was revealed as his former tag-team partner Mo who attacked him and the two brawled until they were separated by officials. Mo and Mabel had a short feud in Memphis Wrestling.

In May 2015, he worked four shows as Sir Mo for Ultimate Championship Wrestling in Nova Scotia, Canada. He returned to the Maritimes in July with partner Lord Deon (Johnson) for three more shows. On July 30, the team - known as MOM2K - won the UCW tag team titles by beating Sidewalk Sam and Homeless Bob in Halifax, Nova Scotia. Currently (January 2019) Horne runs SOAR Championship Wrestling with his wife Denise Jones in Dallas Texas.