PK Freeze is the name of one of Lucas's Special Moves in Super Smash Bros. Brawl. In this game, it is Lucas' Standard Special Move, and it acts very similarly to Ness's PK Flash. When the player uses PK Freeze, Lucas fires a PSI-based snowflake into the air, charging it up its power while the crystal hovers in the air. After the snowflake charges enough, it will explode, freezing anyone in the surrounding area, as well as harshly damaging the players who are hit. Lucas does not have to wait for the snowflake to charge completely, however, but can instead unleash its icy energy when the time seems right. Lucas will stop the attack when he gets hit, much like Ness was stopped if attacked during PK Flash. Compared to PK Flash, PK Freeze travels much further and charges much faster. Unlike Ness' PK Flash, PK Freeze does not seem to grow in size or power when charged.
PK Freeze is one of the many PSI moves used in the EarthBound series. Also like Ness, this technique is a perfect example of PSI techniques being "borrowed" by Smash characters. In MOTHER 3, Lucas did not possess PK Freeze; Kumatora did.