From Creatures Wikia
Syntax: NEW: SIMP family (int) genus (int) species (int) imagefile (string) count (int) first (int) plane (int)
Creates a simple agent of the class specified by the first three arguments, which uses sprites from the file imagefile.c16 or .s16 in the Images directory. The first sprite (POSE 0) will be at an offset of first from the start of the file, and count sprites on from this will be used. The agent will be at the specified plane - generally from 0 (furthest back) to 9000 (near the front).