With the arrival of Comic Con week in San Diego, rumors have emerged online that DC comics characters Oracle, Batwoman and Constantine will make an appearance on the DC-based series airing on the CW network.

According to Bleeding Cool, there have been rumblings that "Supergirl" will feature the appearance of Oracle and Batwoman on its upcoming second season, with the latter to appear in a recurring basis.

In the DC comics lore, Batwoman, aka Kate Kane, became a vigilante after she was saved by Batman. Her father, Colonel Kane, helped with her travels to develop her combat skills. Kate is also in a relationship with police captain Maggie Sawyer, a character who is already on tap to appear on "Supergirl" Season 2.

Oracle, aka Barbara Gordon, is known for her hacking skills and photographic memory in the comics. She founded the Birds of Prey team to fight crime in Gotham City.

The connection of Batwoman to Maggie Sawyer makes it slightly possible that this ongoing rumor is true. However, for Oracle's part, her arrival in National City could be linked with something else the TV series has not yet introduced.

As for Constantine, the publication said that Matt Ryan, who portrays the character, might get the same deal that Wentworth Miller and John Barrowman signed-up for recently. Since the character has already made a crossover appearance on "Arrow," this rumor can be an indication that showrunner Greg Berlanti is planning to include Ryan in DC's universe on TV.

Die-hard fans who are eager to know if these claims are actually being planned might just have to wait a bit more until new developments unfold from Comic Con this week.