[6] He studied and played for the University of the Visayas from 2007 to 2009 and took up Political Science, winning the Cebu Schools Athletic Foundation, Inc. (CESAFI) men's basketball title each year in his three-year stint with UV, as well as the league MVP award in 2008 and 2009, the latter of which he shared with June Mar Fajardo of the University of Cebu.

He successfully teamed up with Kiefer Ravena and Nico Salva to lead Ateneo to two UAAP championships and completing a five-peat.

Greg Slaughter was paired with Japeth Aguilar to form one of the most formidable frontcourt duos in the PBA and was dubbed the "Twin Towers".

[13] In April 2024, Greg Slaughter was listed as a reserve player for the Maharlika Pilipinas Basketball League's Manila SV Batang Sampaloc.

[17] He was also a part of the national team pool in preparation for the 2013 FIBA Asia Championship held in the Philippines but did not make it to the final 12 roster.

He was again invited to the pool that will train to compete in both the 2014 FIBA Basketball World Cup in Spain and the 2014 Asian Games in Incheon, South Korea, but he declined.

[18] He played in the Philippines in the fifth window of the Asia qualifiers for the 2019 FIBA World Cup against Kazakhstan, but he was scoreless and had only one rebound in the game.