Okay, so because I have an unhealthy obsession with this game's crabs, I've been looking up threads and doing some experimentation in regards to the Tiny Catacombs Crab that spawns when you kill the second skele-ball and found out...interesting stuff but nothing amazing. So here goes:
1. So, the TCC attaches to you and follows you but never attacks you. How far away can you get before he stops following you? The answer is apparently forever. I read a thread where someone kept running to opposite ends of an area and it would follow even without seeing you. It gets stuck on stuff a lot but it follows. In my own experiments, I spawned the TCC, got it to lock onto me and then ran to bridge, clearing out enemies as I did. I stood on the opposite side of the bridge and after a long-ass time it found it's way over there. I then ran all the way back to the area with the Carthus Milk Ring and waited forever and it got stuck on a pillar right near where I was after like 15 minutes. I read that someone actually got it to drop down and survive the trip to S
using Force. If you get it that far, it seems to stop and wait in front of the edge of the bridge as if waiting for you to push it down there.
2. If you take the TCC down to S
you can run around the whole area BUT it attaches itself to the large worm/where it spawns so you can't take it into the D
that way or Boss Fight. Otherwise it will follow you anywhere in S
. It does not seem to interact with anything down there, not even it's brother crabs! Although in the course of investigating said less-friendly crabs, one of the ember crabs chilling down there does not actually aggro on you. He just kinda...minds his own business and does whatever cool things crabs do all day. The TCC does not interact with him in any way, which is disappointing on a number of levels, mainly emotional. The TCC will not help you fight H
.
3. If you open up the shortcut to the D
using the ballista you can lead the TCC into the D
but getting it there is extremely difficult with the ballista still firing and your need to be somewhat near it to direct it into the hole. Without the ballista you can't get it into the D
. Really been unable to find anyone who got the TCC in there.
4. If you take the TCC back in the other direction he can only go as far as the Abyss Watchers fog wall. He'll push against it and try to get through but he can't even if you hit or kick him (which broke my fucking heart, I didn't mean it little guy).
5. He gets stuck on W
's fog wall so that's the farthest you can take him in that direction too.
That's pretty much all I've found out. We're probably not going to learn more until you can warp it back to Firelink and level it up 5 times at Yoel to unlock the DLC Crabtorias of the Crabyss.
I might care about crabs too much.
Edit: Oh, you can actually lead him onto the bridge and cut it and he'll survive the fall down to S
. If you drop him down there, he unlocks the Crab Covenant.