Wiktionary
proud as punch
a. (context simile English) Very proud.
Usage examples of "proud as punch".
I am as proud as Punch to think that I once had the honour of being connected with your family.
What was she but a fast little piece making off with someone else's husband, proud as punch to be an unmarried mother?
And there the hussy was, four months gone if a day and as proud as Punch and Mrs Ashpole the same, telling me the banns had been asked.
She was as proud as punch of me, but it startled the daylights out of her.