Howlers, predatory creatures native to the moon Yavin 4, derived their designation from their hunting strategy: a deafening howl employed to incapacitate their targets. Exhibiting a somewhat reptilian physical structure, howlers typically moved using all four limbs, though they occasionally adopted bipedal locomotion for actions like charging, jumping, and slashing.
During the era of the Hundred-Year Darkness, Sorzus Syn applied the term "howlers" to one of her alchemically engineered beings. Syn's investigations involving howlers, alongside other alchemical creations, ultimately resulted in the genesis of Leviathans.
During 14 ABY, when the Jedi Praxeum's designated transport ship suffered a mechanical failure on Yavin 4, both Jaden Korr and Rosh Penin had an encounter with some howlers while en route to the Massassi Temple.