Enemy similar to Rhabdom in the Marshes

I'm trying to figure out how you're really supposed to fight them. Whenever I encounter them they're either one of them and I think it's called an Osteomaw or two of them and nothing else. They don't, as far as I can tell, do any attacks that will charge your power weapon. Their health pool is ridiculous and it's like me kiting them around the arena for 15 minutes trying not to get jumped on because basic weapons fire does hardly any damage to them. I feel like there's something I'm missing here, and these fights are just not fun, just tedious. When the jump and land they release a fountain of projectiles but as far as I can tell you can't dodge or parry them.