Acid spit collects corpses. Maybe bug? Also make sure you bring the saddle into the cave with you, or you will spend many aggravating hours trying to get it to follow you out, as it gets stuck on every little thing.
Not exactly the best combat mount, slow, stamina isn't the best, a little squishy. But a few high levels of these on base defence are pretty good. Put a few in the inner parts of your base (along with the spiders to slow them down) and the will have your enemies armour being melted in seconds!
High level centipedes are very tanky when tamed due to the acidic blood. This means it is a great Dino to protect the base. Also the spit can harvest bodies and cut down trees from far away. Can use as a quetzal defense Dino. Just set to turret mode.
These things have a great deal of health and can not be knocked back. Pumping these things in health is probably one of your most viable options, as it takes crazy a lot of points for speed to be of use, which they aren't built for anyhow.