to get keratin you must sacrifice the turtles

Me when I first started and got to level 38 where are all the turtles

Bow arrow in turtle face axe best results for it

On ragnarok, at the highlands beaches you can find beached basilo carcasses that give a lot of keratin, spoiled meat, oil and hide. (Use a chainsaw for best results.)

Kill the turtles since this is not Minecraft

Harvest a dead whale on a beach with your pickaxe. Tons of keratin, oil and rotten meat to make narcotics.

Kentros are pretty good for keratin

On Aberration, there are keratin bones in the surface entrances. Mining Drills and Tek Stryder excavation drills mine these ridiculously well

Thorny devils give high amounts of Keratin and are everywhere in sand biomes