Gagadon ("Gaga tooth") is an extinct genus of even-toed ungulate that lived in the early Eocene of North America. The type and only known species, Gagadon minimonstrum, was described in 2014 based on lower teeth and jaw fragments found in the Wasatch Formation of Bitter Creek, Wyoming. The genus is named in honor of the singer Lady Gaga, while the species name minimonstrum ("mini monster") refers simultaneously to the small size and presence of unusual cusps on the teeth and to Gaga's name for her fans, the "little monsters".