He's cute, cuddly and fun but be careful when you feed him.
• The gribble is an NPC who wanders randomly around (We used the “route” primitive).
• A variable is set to store the Gribble's "hunger" level. At day 3 without being fed the Gribble follows a Sim around to bug them to feed it. At day 4 it turns into a bad gribble. On day 6 it dies.
• Bad and good gribbles will occasionally fight each other (random chance).
• Good gribble adds to the environment on the Sims lot.
• Bad gribble takes away from the environment.