Next month, Barry Allen from The Flash will crossover to visit Supergirl on CBS. Last night, the girl of steal was briefly seen on The CW series — as were several others from the DC Comics universe multiverse.

In the episode “Welcome to Earth-2”, Barry, Cisco, and Harrison Wells travel to an alternate reality using the speed canon. Before they get there, they pass characters that comics fans will recognize — including Supergirl and The Flash from the 1990s CBS series. The latter was played by John Wesley Shipp who plays Barry’s father, Henry, on the current series.

Eagle-eyed viewers could also pick out images of Grodd the gorilla, cowboy Jonah Hex (likely Johnathon Schaech from the upcoming 11th episode of DC’s Legends of Tomorrow), a Legion of Super-Heroes flight ring (perhaps the characters will appear in a future episode of one of the DC series or, this is a nod to Smallville), and an alternate version of Green Arrow (possibly Connor Hawk).

Other episode Easter eggs include shout-outs to Aquaman’s Atlantis and a phone that showed the first names of the alter-egos of Batman, Green Lantern, and Wonder Woman on speed dial.

The second part of the episode airs next week — “Escape from Earth-2”. Perhaps we’ll see more cameos then. Here are the cameo clips:

What do you think? Did you enjoy the Easter eggs? How many did you notice? Would you like to see other characters/series reference on the next episode?