Synonyms for Pachydermatous (same or very similar meaning)
WordNet sense 1 (of or relating to or characteristic of pachyderms):
pachydermal, pachydermic, pachydermousWordNet sense 2 (emotionally hardened):
callous, indurateWordNet sense 3 (deficient in human sensibility; not mentally or morally sensitive):
insensitiveFrom the ODE community, based on WordNetadd/edit