Carla Yeager

Carla Yeager was the mother of Eren Yeager and of her adopted daughter, Mikasa Ackerman. She plays a major role posthumously as her death is the main driving force behind Eren's desire to join the Survey Corps and avenger her mother's death at the hands of the Titans.

History
Long before the beginning of the series, Carla Yeager was a known prostitute who's sexual acts and encounters would become legendary all throughout the empire. According to Niles Dok, the Commander of the Military Police, every man over 30 heard of Carla and she's said to have gone through entire villages in a day, and according to Pastor Nick, she was "The FINEST HOE THE EMPIRE HAD EVER SEEN" and how she could "SUCK A DICK LIKE IT WAS SCRIPTURE." Her days as a prostitute ended with her marriage to Grisha Yeager, but she was far from forgotten by the rest of the empire, though Eren remained oblivious to what she did. According to Hannes, a plague was caused by Carla and Grisha stopped it and cured her of nearly every STD that she inherited. She then had Eren and adopted Mikasa after her parents were murdered and she was kidnapped, but later rescued by Eren, from human traffickers.

Carla makes her first appearance in Episode 1: Big Trouble in Little Shiganshina where she welcomes her children home after they return from collecting sticks. She then pulls at Eren's ear and mockingly sings how "Those who don't get wood are no good" knowing that her son didn't get sticks because of his laziness. At dinner, Eren says that he heard interesting things from the guards (obviously refering to Carla's days as a prostitute), but is interrupted when Mikasa states his intention on joining the Survey Corps (refered to as the Recon Corps) which shocks Carla. She goes on about how shocked she is at Eren hiding his intention on joining the Survey Corps a secret despite him saying that he abandoned the intention, but stops and is hesitant when Eren asks if she's sure she hadn't done something similiar to what he did once more referencing her whoring days.

After Grisha leaves the house for business, she re-affirms her opposition to Eren joining the Survey Corps, but he runs off after saying how he hates her lying about her filthy past. She then tells Mikasa to protect him from the truth at all costs. A couple of hours later and the Colossal Titan appears and kicks down Wall Maria exposing the entire population to the Titans who come in and devour anyone they see. Carla is crushed beneath the wreckage of their house and her legs are crushed. Eren and Mikasa try lifting up the wreckage, but to no avail, but not after Carla says that she feels Mikasa lifting up the wreckage while Eren can't do that and compares them lifting the wreckage to a death match between Iron Man and Jiminy Cricket. After the wreckage can't be lifted and her feamer's broke, she tells them to run before Hannes shows up to attack a nearby Titan coming to kill them. Hannes is horrified by the Titan coming and follows Carla's wish and rescues her children while she's left to die. Eren shouts how he hates that Carla and Hannes' relationship was kept secret from him, but sees her die and is horrified by it and thus, is motivated to join the military and avenge her.