Keratin is obtained from creatures with shells, horns, or spikes in ARK: Survival Ascended. It's used as a substitute for Chitin in crafting cementing paste and saddles.
Node yields assume the base harvest HP from game data (e.g. 1000 for Redwood trees, 620 for Metal nodes). In-game, trees and rocks with bAllowHarvestHealthScalinghave per-instance HP that varies with the node's size, so actual yields per node will vary. The values shown represent the average.
The Pelagornis is the best Keratin farmer with a 13.3x gather multiplier from game data. The Deinotherium is the runner-up with 2x.