This weapon is inspired by an illustration made by @DecomposedTaco.

Parts Used

I started with the base game Fire Gecko mesh and added the flak vest from the NCR Trooper Armor, one of the leg straps from the Armored Vault Suit, the chain from the Chained Prostitute Outfit, and the handle from the legacy-content Mesmetron.

Perks and Challenges

The following properties, perks and challenges apply to this weapon:

• Pyromaniac

Procurement

This weapon can be obtained by crafting either one of two items at any workbench.

The Incubator Method

Once the incubator has been crafted, as soon as it is equipped, a random number of egg cycles (between 7 and 10) will be generated. To hatch the egg, you must walk for that number of egg cycles while wearing the incubator. Each egg cycle consists of 300 “steps,” calculated as the number of seconds spent running (walking doesn't count) with the incubator equipped. You can use the console command set aaaGLOBIncubatorStepCount to # to adjust the number of “steps” per egg cycle. Once all egg cycles have been completed, the egg will hatch automatically, spawning a domesticated fire gecko beside you.

The Harness Method (Wild Wasteland)

After crafting the harness, you must locate any fire gecko in the worldspace and render it unconscious. Then, activating the unconscious gecko will give you the option to attach the harness, at which point it gets replaced by a domesticated fire gecko.