Reptile (aka corrosive FL4K)

Fl4k build by pestopartyy updated 7 hours ago
Login to rate this build!

Themed after the green-clad ninja of the same name from Mortal Kombat. Focuses on both emulating Reptile and using corrosive damage as much as possible.

Believe it or not, this build actually works really well on even pre-patch M10 (mainly because of the Reflux but still). I don't really like takedowns so I can't say much on its viability there but it can definitely handle slaughters and other harder mobbing areas like the Anvil.


Note: All gear should be corrosive (if possible) for the sake in the theme.

Main Guns

  • Reflux - This is your Acid Spit. Great for mobbing and proccing Head Count. This is the main gun to use while you're out of Fade Away. It received a fairly hefty buff as part of the DLC3 patch's blanket Hyperion shotgun buff so it's even more ridiculous now.
  • Gargoyle - Can also thematically work as your Acid Spit. Great for single-target damage; not so much for general mobbing because of the ammo cost.
  • Plaguebearer - This is your Force Ball and also your best choice if you're looking to make the most out of your Fade Away shots. It's great for both crowd control and single-target damage but it generally works best for when you want to take out an enemy without breaking Fade Away. The homing projectiles work great with Leave No Trace and make this gun very ammo-efficient on FL4K.

Other Guns

  • The Lob - Can also work as your Force Ball albeit not as well as the Plaguebearer can. This used to be this build's main weapon before Mayhem 2.0 but now it's outclassed by the Reflux and Plaguebearer in both of this build's main gun roles. Still, it works great for mobbing especially with a 300/90 anoint.
  • Breath of the Dying - Every kombatant needs a Fatality, and this assault rifle has one of the coolest on-kill effects in the game (it's also fairly similar to Reptile's "Weight Loss" Fatality from MK9). It also does a solid job at killing on M10. Note that sometimes the nova won't proc because of the ASE corrosive shield anoint.
  • Hornet - This is a Reptile build not a D'Vorah build. Still, it does decent damage at M10 and is definitely less ammo-hungry than the Gargoyle.


  • One-Shotter' Shield - General best in slot here; great for one-shotting things (as the name implies). I prefer the Pangolin variant because it has the fastest recharge. Get one with corrosive resistance for bonus thematic points.
  • Impaler - You're probably wondering, "what is this garbage shield with terrible damage doing in this build?" Well it's corrosive-only (which goes well with the theme), it has a fast recharge and it spends more time being full than any other shield here which gives it the most synergy with Topped Off. It's also parts-locked and is much easier to find than a One-Shotter.
  • Old God - Great for long-term damage but the long recharge gives it little synergy with Topped Off. Still great for bossing because you're probably constantly shooting and proccing Head Count anyway.

Class Mods

  • DE4DEYE - Shields are the health type that corrosion does worst against and many enemies in the game have them as a non-bottom bar so that 35% V2 bonus helps with getting past them. The Two F4ng boost doesn't really do anything for multi-listed pellet guns like the Reflux but it is great for getting double Plaguebearer shots and the like. Plus Reptile's supposed to be all sneaky and assassin-y so this works well with the theme.
  • Bounty Hunter, St4ckbot - These also work well and in a lot of cases even better than the DE4DEYE; I just don't like them as much and plus they don't feel as Reptile-y.

Grenade Mods

  • Hunter-Seeker - Good for stacking the Pearl and consecutive hits bonuses and occasionally proccing Head Count and/or Leave No Trace as well.
  • Acid Burn, NOG Potion #9 - Obviously very situational but nonetheless good for making enemies attack you less which is especially good for FL4K. Note that Reptile has the power of hypnosis in the old Malibu comic series so this does in fact work with the theme.


  • Flesh Melter - Gotta keep with the corrosive theme here. Not the greatest for bossing but for mobbing with corrosive weapons it's absolutely one of the best choices out there. Reflux, Plaguebearer and BOTD (when you actually get the nova) in particular help a lot with this due to their crowd control potential. The exact artifact is up to you; I like Otto Idol for the survivability but that's just me.
  • Caustic Coast - If you feel like replicating Reptile's Slide then try this instead. Not really helpful for M10 but still fun.
  • Corrosive Stone - Same as Caustic Coast but this time for replicating Reptile's melee capabilities. (note: getting melee kills as FL4K is absolutely possible thanks to Groundbreaker)
  • Pearl of Ineffable Knowledge - Really only needed for bosses honestly.


Obviously there's the skill tree below but I'm including this section just to justify certain skill choices I've made.

  • Fade Away - Reptile's trademark ability is to turn invisible so of course it's going to be in this build.
  • Spiderant Countess - Generally not a killer for this build (although thanks to Groundbreaker she can occasionally instagib trash mobs) but all her attacks are corrosive so in the event that she does land a killing blow you'll get a Flesh Melter stack. That and also the action command is great for aggro; it's basically a mini-Gamma Burst.
  • Two F4ng - Mainly for the Plaguebearer but also the Lob sometimes. Also good for if you get bored and decide to pull out an Unseen Threat or some other single-listed pellet gun. Plus its skill icon is literally a reptile so of course this build has to have it.
  • Megavore - In addition to being, well, Megavore, it also fits the Reptile theme because one of Reptile's most famous fatalities is the one where he eats his opponent's head off so course you'll want your voring capabilities to be truly mega.


  • Guns - For the single-shot weapons either 300/90 or ASA 200 depending on how dependent said weapon is on multiple hits. For multi-shot weapons you'll want to go with ASE corrosive or ASE 100 although consecutive hits and ASE splash also work great for the Reflux and Gargoyle, respectively.
  • Shields, Grenade Mods - You definitely want at least ASE corrosive for one of them. As for the second one, another ASE elemental anoint (radiation works best because it covers the health types that corrosion is weak against) will provide the most potential damage but OGT 25 can come fairly close, can be activated more easily and is better for accruing Flesh Melter stacks and activating BOTD novas.

Stat Bonuses

These are the ones which I generally feel are the most important for this build.

  • Corrosive Damage - This build only uses corrosive weapons so this is a no-brainer. Plus you won't always have Flesh Melter stacks so it's nice to have this as something of a safety net.
  • Magazine Size - This is one of the best stat rolls in the game period and will greatly help any non-COV gun; definitely a big help for the Reflux.
  • [Weapon Type] Damage - V2 damage is always good and weapon type bonuses are V2 so they're good. I like shotgun damage in particular for this build because its most-used weapon is a shotgun.
  • Splash Damage Radius - This has amazing synergy with Hollow Point which FL4K themself also has amazing synergy with. Also great for helping guns like the Gargoyle mob better and taking out Buddy Systems without actually shooting at them.

Mayhem Modifiers

Any modifier combination of your choice is fine but avoid Acid Reign and Dazed and Infused like the plague. This build uses almost exclusively corrosive damage so corrosion-immune enemies are naturally the worst thing for it.


Use Fade Away as much as possible; this is especially good for having amp damage ready. When not in Fade Away, use the Reflux to proc Head Count (and also kill enemies). Against singular enemies the Gargoyle and Plaguebearer are better choices; if attacking and Fade aren't viable options then run away and let Topped Off bring Fade back for you.

One-shot weapons like the Plaguebearer can work outside of Fade Away but in general I prefer saving them for Fade in order to maximize their damage potential.


Similar Fl4k builds