thunder beast
nounEtymology Calque of taxonomic name Brontotheriidae, which is derived from Ancient Greek βροντή (brontḗ, “thunder”) + θηρίον (thēríon, “beast”) + -idae. ]
1
Any of the family †Brontotheriidae of extinct odd-toed ungulates that superficially resemble rhinos, some of which develop bony nose horns.