Kid Knee is a Strontium Dog.
He teams up with Johnny Alpha and Wulf Sternhammer to hunt down ‘The Mutator’ in the 2000ad story – ‘The Kid Knee Caper’ (2000ad progs 228-233).
Kid finds The Mutator, but dies in the final battle with him.
The story was reprinted in the Judge Dredd Megazine (volume four) issues 9 and 10.