A KnightCritter moves like a Knight in chess. It moves two squares veritcally and one horizontally or two horizontally and one vertically. Objects adjacent to it do not impede its path. Below is a diagram of how a Knight can move.
-------- -------- -*-*---- *---*--- --N----- *---*--- -*-*---- --------
Here, the KnightCritter is represented by the N. The asterisks represent the set of squares onto which the KnightCritter can move. In GridWorld, a KnightCritter will NOT move onto a location that is occupied by another object.