The comic featuring the phoenix is "The Flash." The character of the phoenix, known as "The Phoenix," is a recurring villain in the DC Comics universe. The Phoenix first appeared in "The Flash" 123, published in 1961, and was created by writer John Broome and artist Carmine Infantino. The character is a master of illusion and often uses his powers to manipulate the Flash and other heroes. The Phoenix's ability to transform into a fiery bird-like creature, reminiscent of the mythical phoenix, adds a unique and memorable element to the comic series.

The inclusion of the phoenix in "The Flash" is significant for several reasons. Firstly, the phoenix is a powerful and symbolic character that adds depth to the narrative. The mythical phoenix is often associated with rebirth and renewal, which aligns with the themes of the comic series. The Flash, as a character, embodies speed and time travel, and the addition of the phoenix as a recurring villain introduces a new layer of complexity to the storylines. Additionally, the phoenix's ability to transform into a fiery bird-like creature provides a visually striking and memorable depiction that resonates with readers.

Data from the sales of "The Flash" comics during the period when the Phoenix character was introduced supports the significance of the character. According to a report by ICv2, "The Flash" 123, which featured the debut of the Phoenix, sold over 1 million copies. This indicates a high level of interest and engagement from readers, suggesting that the character was well-received and contributed to the popularity of the series. The recurring appearances of the Phoenix in various "The Flash" storylines further solidify the character's status as an iconic figure in the comic book universe.