Well, if we consider Mr Magoo, he often gets into comical yet sometimes sad situations due to his extreme nearsightedness. It might be a story where his clumsiness and inability to see clearly result in him missing out on something important. For example, he might have been looking forward to a special event, but because of his vision problems, he ended up at the wrong place and missed it, making it a sad story for him.
To figure out who sounds like Mr. Magoo in a Christmas story, we'd need to consider the voices of various characters and compare them. It could be a character who has a similar pattern of speech or vocal inflections. Without knowing more about the specific story, it's a bit of a mystery.
The setting could be an important element too. If the story is set in a busy city where everything is fast - paced and he has to constantly struggle to keep up because of his eyesight, it can make for a sad story. Imagine him trying to cross the street but being unable to tell when it's safe due to his nearsightedness, and people shouting at him. His internal struggle to fit in and be normal in such an environment is a key part of what could make the 'Mr Magoo Sad Story' sad.