GIMP Animated Brush
GIMP Animated Brush is one of the formats used by the GIMP image editor to store a brush or texture. It appears to be a wrapper format for multiple encapsulated GIMP Brush files. Despite its name, it would be a stretch to consider it to be an animation format.
A .gih file apparently begins with a plain text header. The first line contains the brush name. The second begins with the bits/pixel(?), then a space, then a space-separated list of attributes (such as "ncells:", "cellwidth:", "cols:").