Ice knack is a variant of the original knack. In Knack 1, it first appears to shut down gates while the ice melts. In knack 2, it reaapears without the melting function.
Because ice Knack is a variant of the original knack, it will have speacial powers. pressing square will render upon your opponents an ice slash. Holding down square will unleash ice breath, a move that disables your opponents mobility for a short while. It is also a temporary replacement for the multi-punch attack.