Destroy the Snagglebeast and Find a new ship are missions in Ratchet & Clank. After stepping into the Ring of Heroes, Qwark betrays Ratchet and Clank, throwing them together into a pit with a Blargian snagglebeast. After its defeat, completing the mission "Destroy the Snagglebeast", they were stuck inside the cavern, starting the follow-up mission "Find a new ship". They managed to find both a new ship, Qwark's tour shuttle, and an infobot with coordinates to planet Batalia.
The snagglebeast is powerful, but predictable, and its attacks are easy to avoid. Its primary choice of offense is to send fiery shockwaves along the floor, which can be easily jumped over. When you are up close, he will shoot fireballs from his palms. Simply move away to avoid these. Thirdly, he will shoot a laser if you are too far away. The laser is harmless, but draws a line along the ground that erupts into flames. Out of all available weapons, the Blaster is the most useful, with the Mine Glove and Bomb Glove being useful in case you run out of ammunition, though there are plenty of ammo crates in the area. The Glove of Doom is useful as well, but its agents are instantly destroyed by the boss' shockwaves, requiring you to get close or wait for it to initiate another attack.
Once one-sixth of the Snagglebeast's hit points, one part of its health bar, has been depleted, it will create an impenetrable barrier around it and proceed to follow you directly while shooting fireballs. You must lure it across one of three bridges. This will cause it to break, dumping the snagglebeast into the lava. This will disable its shielding, dealing enough damage to remove another part of its health bar. When the beast jumps back out, he will initiate a single shockwave, which is larger in size, but can be easily avoided due to it short radius. The destroyed bridges leave behind separate platforms that you can still use to move around. Repeat this twice more, though be careful of an additional ability in the final part of the boss fight, as it will create a gust of wind, removing all your ammo and scattering it in the area behind you.
Once defeated, completing the mission "Destroy the Snagglebeast", you immediately begin the "Find a new ship" mission, which is easily completed by finding the only exit in the area.