Hera is a Twi’lek and is voiced by actress Vanessa Marshall. She is the 7th and final major character to be introduced from the new show Star Wars: Rebels...
For the video introduction go to Entertainment Weekly:
“She is a very strong-minded character,” says Rebels executive producer Dave Filoni, “kind of the heart of the group, keeps everyone together when they would otherwise fall apart.”
“Every time we get a script I’m breathless with anticipation,” Marshall adds, “because I want to see where we’re going too.”
So 6 rebels and only 1 bad guy? I hope there are more in the actual show.
Here's Numa with Cham Syndulla from The Clone Wars. Probably they are somehow related with Hera Syndulla.