Smacker is a video format and codec developed by RAD Game Tools to assist implementing full motion video into video games. It was released in 1994 at the height of the FMV boom, and succeeded by Bink Video in 1999.
In LEGO Island
Smacker is one of two animation/movie file formats used in LEGO Island, the other being FLIC. While LEGO Island is obviously not an "FMV game", it does contain a handful of FMV sequences: