OK, so I figured it might be prudent to help players advance by sharing boss strategies! Feel free to add you own startegies that have proven helpful or effective in defeating enemies.
BE AWARE THAT THIS THREAD, BY NATURE, CONTAINS SPOILERS!!!
So don't look if you want a "pure", unspoiled experience.
Saenus Beefuarus Boss
Codename: Azure Scissors
Azure scissors is an aggressive but easy(-ish) boss who capitalizes on the Saenus Beefuarus species combat zooid, thankfully not doubling up on his species' mouth parts abilities to stick victims in a loop of being blown into pincers. it's ONLY weapons are those nasty pincers. assuming you are starting with Advena, The mouth part is your best friend with it's poison vomit attack. Get Azure Scissors to charge you by entering his line of sight and back-peddle down through the corridor you spawned in as you continuously belch poison, switching with dash if he manages to start closing and putting you in pinching range. position your mouths to launch poison in a V arc, in order to knock out Azure's scissors quickly. Once he's been (literally) disarmed, you need only fight the force of his mouth pusher zooids to get in close and poison his main part to kill him, or swap out one of your mouths for a spike if you want to give him a good shanking, although you will need that second mouth, and a third, for the next boss!