This is especially true for legendary pokemon based on real-world myths. Whether it's due to the cultural art style or the vagueness of their verbal descriptions, most of these real-world legends are a lot less aesthetically pleasing than the pokemon they were transposed as.
*bulbagarden.net image removed*Articuno is based on the Roc, a mythical bird from the Arctic that was said to torment sailors and carry off ships:
*bulbagarden.net image removed*Zapdos is based on the Native American thunder bird that was said to bring thunder and lightning when it clapped its wings.
*bulbagarden.net image removed*Moltres is based on the Suzaku of Japanese legend that is said to be the protector of the southern seas:
*bulbagarden.net image removed*Raikou is based off the Raiju, a thunder-demon from Japanese mythology:
*bulbagarden.net image removed*Entei is based on the lion-dogs of Chinese architecutre, which are said to have mythical protective qualities and adorn holy temples:
*bulbagarden.net image removed*Suicune is believed to be a canine representation of Fujin, a Japanese god of winds that is often depicted as wearing leopard skins.
*bulbagarden.net image removed*Lugia is based on a Ryujin, a Japense dragon god that guards the sea:
*bulbagarden.net image removed*Ho-oh is based off of the Fenghuang, a Chinese pheonix that is said to bring rebirth to those worthy of it: