From Creatures Wikia
REPS n (int) .. REPE
This creates a bounded loop. REPS opens the loop block and REPE closes it again. The loop block is repeated n times, and then execution continues at the point after REPE.
SETV va01 1 REPS va00 MULV va01 va00 SUBV va00 1 REPE OUTV va01