This is the person you claim you already made plans with in order to get out of doing something with somebody you are trying to avoid hanging out with. Often used to ditch a girlfriend or dinner at the parents house.
"Thank god I used you as an escape goat, almost had to goto my sister's birthday party!"
"No problem man, at least something good came out of me getting in that terrible car accident"
"Hey wanna goto a movie later baby?"
"Yeah sure. Oh! Shoot I forgot, I already had plans with Taylor"
"You're just using him as an escape goat aren't you!"