Ah! There is one that I'll always remember...
To start out the story, note that each of the limbs of the creatures can take damage. Like, if you hit a lizards arm or leg with a rock, it can cripple that limb, meaning that the lizard cant use it for locomotion; it will move slower, and if it is trying to climb a pole or something and it weighs too much for the other limbs to support it and will probably slide down, with its broken arm or leg dangling, etc.
Another thing to note is that the creatures pathfinding will learn from its mistakes, so if it attempts a path a few times and is unable to for whatever reason, it will seek out alternate routes.
SO! We are testing all this on a white lizard, which can normally walk on walls etc., making sure that when its limbs break, its pathfinding AI chooses a floor based route rather than trying to climb a wall and fall off over and over. We break the legs and then the arms and everything seems to be fine.
What we DIDNT take into consideration was its tongue. White lizards have a long sticky tongue like a frogs that can be used to grab onto prey and into its jaws. So after the lizards legs are crippled and it should be just a pile of twitching meat, we notice the tongue starts flailing around. Then it starts sticking to things. Then the lizard starts PULLING ITSELF ALONG using its tongue, grabbing onto things, reeling itself over, etc etc. :O :O :O
None of that was programmed or intended in any way. The pathfinding AI just found a way to solve the locomotion problem using the limbs it had available. But it was SPOOKY AF.