Jägermonster/Mad

Trolls
In all seriousness, comparison with trolls, the ogres of Norse mythology, yields some interesting similarities.

Hearing and DNA
While Jaegers have a keen sense of smell, evidence suggest their hearing may be relatively poor. Combined with the rather odd (and varied) appearance of their skin, this suggests a GJB2 mutation (i.e., change in the gene coding for gap junction protein beta 2). GJB2 mutations are relatively common in the general population because, while when paired they can cause congenital deafness, single copies tend to confer "improved wound healing and perhaps reduced susceptibility to bacterial infection."