Convor

The Convor (Convorees being the plural form) was a small species of owl-like bird native to several planets throughout the galaxy. It seemed to have an unknown affinity with the Force.

Star Wars Rebels
A convor appeared in the conclusion of the episode "The Mystery of Chopper Base", when Ahsoka Tano says to Ezra Bridger that the Force becomes more mysterious as one learns more about it.

Another convor appears in "Twilight of the Apprentice" at the conclusion of Darth Vader and Ahsoka Tano, watching Darth Vader limp away from the destroyed Sith Temple on Malachor before flying away, which pans to the image of Ahsoka entering the ruined temple.

Trivia

 * The Convor is named for Dave Filoni's wife, Anne Convery.
 * When questioned during an interview about its appearances in Star Wars Rebels, Dave Filoni indicated that the creature's appearance had a deeper meaning, stating: "In some ways, I could say that it's a messenger, it's an observer. It is definitely something. And I would suggest – I would rather have fans debate – but I would suggest to say that whatever that thing is an avatar of has actually appeared in the animated Star Wars universe before. So decrypt from there... Have a fun summer!"