Amazing mod, I would like to request that you add compatibility for the mods Cold Biters (https://mods.factorio.com/mod/Cold_biters) and Explosive Biters (https://mods.factorio.com/mod/Explosive_biters) they add biters of size leviathan that are much stronger then the normal leviathan biters and i want to get more for them then a small.

Can you provide the names of those biters? (Preferable the internal name, where you can see their name by hovering over in F5 debug mode.)
I can add them to category V (and VII, ...) of loot tier, if you do not suggest otherwise setting.

explosive-leviathan-biter leviathan-explosive-spitter leviathan-cold-biter leviathan-cold-spitter (default 50 000 health) (category V or VI?)
mother-cold-spitter mother-explosive-spitter (default 100 000 health) (category VII or VIII?)

other options:
if you just search for leviathan you would probably get a couple of other free mods out of it
alternatively you could make loot be a function of health to be fully mod compatible

Just released 0.17.5, which supports the above-mentioned two mods.
Just a point to note: Cold Biters mod option "Enable Alien Loot and Cold Warfare" should be turned off. Because MFerrari wrote a buggy code, not allowing different loot tables in those units.

Cold biters loot table changed in the new version, as suggested, Schall

Wonderful! Just tested Cold Biters 0.17.9, and it works with both the option on/off now.

thanks, both of you

Found another mod compatibility issue, Hexi's Resistant Biters adds types of bitters that cannot be damaged by certain damage types. these are not currently working with this mod
names are of the form big-bitter-resistlaser behemoth-spitter-resistphysical medium-bitter-resistfire small-spitter-resistlaser.
P.S. apologies for giving you 3 things all at once

If you spelled correctly (that means that mod spelled it wrongly), then it is the name pattern failed in recognizing it.
There are two options, either will make it work:
1. Proper spelling on his/her mod, like "big-biter-*", "medium-biter-*".
2. Function call from his/her mod in data-updates.lua or data-final-fixes.lua (see FAQ for details).

if mods["SchallAlienLoot"] then
SchallAlienLoot_add_mover("medium-bitter-resistfire", 2)
SchallAlienLoot_add_mover("big-bitter-resistlaser", 3)
end

I am willing to add extra name patterns if they make sense (like "giant", "huge", whatever). BUT adding extra name patterns for wrong spellings is something I do not want to do.
This mod auto-recognize the following name patterns as unit (movers):

"%-biter$", "%-biter%-", "%-spitter$", "%-spitter%-"

OK, I have Reproted this to Hexicube (the mod owner) I also forgot originally to link the mod so here it is
https://mods.factorio.com/mod/Hexi_Resist_Biters

My mod makes changes in data-final-fixes.lua, I'll change mine to use data.lua since I don't dynamically look for other biter variants.

Considering the nature of your hooking into other mods, you should probably be using data-final-fixes.lua.

Alright, so it is not simply caused by spelling mistakes, as reported by DeadlyKitten.
From wrong statements drawn wrong conclusions.
Good it is solved now, I assume.

I cannot find out the link of the thread on forum, but it says the general practices for different data stages are:
1/ data.lua: Adding items, entities, and whatever.
2/ data-updates.lua: Changing properties, relations, etc.
3/ data-final-fixes.lua: Fixing what cannot be done in data-updates.

So I believe adding biter variants should be done in data.lua stage. Even if having to look for other modded biters/spitters, I observed the common practice (in most enemy mods) is to use optional dependencies to make sure those are loaded before theirs, but still in data.lua stage.

Since most (if not all) enemy units are defined in data.lua stage, and this mod changes the loot properties, I think it is perfectly fine to modify loots in data-updates.lua. I made the function call (stated in FAQ) for other mods to use, if they really decided to add units in later stages.
I could move it to data-final-fixes.lua if it is needed in the future, but for now there is no absolute need to do so.

Thanks both of you