If you're like me and don't have as much manual dexterity as maybe you once did, try this: When the level loads, draw your weapons of choice and get in a few shots as you run a few steps to the left or right.
Roll...
...holster guns, and drop back and grab the edge of the platform.
Now wait for the mutant to lose interest and go back to the door.
When it does, pull up and shoot at it until it approaches.
Then holster your guns, hop back to dangle again, and repeat.
This can take a while, depending on which weapons you're using. Also, if you hang in the wrong place, the mutant can reach under and grab Lara. The best spots seem to be the corners farthest from the door (northeast or southeast), with Lara's back to the side (north or south) walls. If you hang there and wait for the mutant to go back to the wall before pulling up, it then takes the beast longer to move toward you, so you'll get more shots in each time. I've also never seen the mutant try to grab Lara here.
One warning: If you let the mutant get too close before Lara goes over the edge, it may start pounding the floor and refuse to move away.
Either reload or try traversing along the edge toward the rear wall...
...
...then back to the outer corner. Lara will lose some health, presumably as a result of the mutant's stomping on her hands, but it should move off again.
Then you can pull up, fire off a few rounds, and drop hang hang once more.
Repeat until the boss's health bar is depleted. Stop shooting to conserve ammo.
Then just wait for it to keel over and explode.
DARK MODE: Even with brightness adjusted, dark images on a light background can be hard to see. May I suggest a reputable dark mode browser extension, such as Dark Reader? (Download only from trusted sites, like darkreader.org or your browser's web store.)
Walkthrough text and diagrams copyright © Stellalune (email ). Feel free to copy or print this walkthrough for personal use. By all means, share it with friends, but please include this credit line so people can send me their feedback. No part of this walkthrough may be reproduced on another site without permission.