Ermahgerda lisped pronunciation of “oh my god,” The phonetically written captions are meant to sound like a speech impediment caused by the use of an orthodontic retainer, often using the snowclone template “Ermahgerd X.”
Ada : ermehgwerd I LERV U SER MAHCH
Sam : Why do you speak like this?
Ada : I HERV A RERTERNER ERN
Ada : Ermehgwerd did you see that new meme on 9gag?
Sam : Oh my god, wherer?