Here's how the group meet Selena in Brian and the Eeveelution Family's Adventures of Transformers: The Last Knight.
Selena: Are you Snoopy?
[Brian turns around and sees a young filly pegasus]
Selena: Snoopy. From the Peanuts franchise.
Brian: Oh, no. I'm a labrador, Snoopy's a beagle. I'm Brian.
Selena: Please to meet you. You know, I'm an orphan, and someday I'm gonna get away from this human and Transformers civil war.
Sylveon: You're an orphan?
Selena: Mm-hmm. All my life.
Vinny: How long have you been here?
Selena: Since the battle of Hong Kong. My mom and I were having a vacation... but we've got separated and she got killed by one of the robots.
Cinderella Oh, you poor little girl.
Selena: I'm a equine, and my name is Selena.
Cinderella: I'm sorry. I don't fully understand.
Peter: Hey guys. What's this? [shows them a folded Pit Droid, but turns it on] Oh! Wait! Wait! [falls over]
Pit Droid: [laughs]
Peter: [grabs him in the throat] Gotcha!
[Peter and the Pit Droid look at Selena as the Pit Droid kicks him in the sweet spot]
Selena: Hit the nose.
Peter: Oh! [releases him] Well, why didn't you say so? [he taps the nose as the Pit Droid folds back]