The Phoenix is occasionally pictured as endowed with nimbus, which emphasizes the bird's sole connection with the Sun in ancient or medieval literature and art. In the oldest images found, they appear to have seven rays. They are also described as having a crest of feathers on its head and Ezekiel the Dramatist even compared it to a rooster.

According to popular belief, the Phoenix is colorful and vibrant. However, there is no proof of its exact coloration. Tacitus claims that the color on its coat made it stand out from other birds. Some believe that it had peacock-like or red and yellow coloring. Ezekiel the Dramatist clarified that it's legs are red and it's eyes are a striking yellow color, but Lactantius claimed that it's eyes were a sapphire blue color and that it's legs were coated with scales of yellow/gold with rose-colored talons.

Solinus, Herodotus, Philostratus, and Pliny all claim that the Phoenix is the size of an eagle, while Ezekiel and Lactantius claim that it is the size of an ostrich.

There are many theories as to what these mysterious birds look like. It's hard to be sure, considering that they are very rare. They can be used as pets for witches or wizards in the wizarding world if you're lucky. Albus Percival Wulfric Brian Dumbledore, the headmaster at Hogwarts School of Witchcraft and Wizardry, has a pet Phoenix, and his Patronus is also a Phoenix. This Phoenix's name is Fawkes, and he is very loyal to Professor Dumbledore. This Phoenix is shown to be red with a tinge of orange/gold/yellow.