The 19-year-old has linked up with the Pilgrims on an initial one-year contract following his departure from Stadium:MK amid interest from a host of clubs, including a handful of Football League outfits.
He trained with his new United team-mates for the first time on Saturday morning as preparations for the new Vanarama National League North campaign intensify.
"The centre forward position is one we have been patient on," reflected United boss Adam Murray. "We wanted someone who was hungry to score goals and had the movement and intelligence to get themselves into constant goalscoring situations.
"In Kabby we believe we have found a young man with those attributes. He is quick, powerful and intelligent around the box. He scored 42 goals in 25 games for MK Dons at under-18s level and came to National League North and scored five in 10 for Corby Town a couple of seasons ago, so we believe he has goals in him.
"The next stage for Kabby is a settled environment where his focus is on one club and scoring goals in that environment. We are very pleased he chose us as the club that he wants to be part of.
"He's played a number of times for MK Dons' first team and will bring a real quality to the team."