Eddie teaches Beaver to say in Spanish "usted tiene una cara como puerco." 'Puerco' is the operative word, meaning 'pig'. As Eddie explains to Wally, the statement in English means 'you have a face like a pig'.
There's another inconsistency here regarding Wally's friendship with Eddie. Wally, speaking to Ward in the garage, says that he's known Eddie since second grade. But in Nobody Loves Me (1962), the boys were friends from at least age 2; Eddie threw a temper tantrum at Wally's third birthday party because Wally didn't open his present first.