The phrase "big as life and twice as natural" is a colloquial expression used to describe something or someone that is particularly impressive or remarkable. There are many synonyms that can be used to convey a similar meaning, such as "larger than life," "grandiose," "monumental," "majestic," "imposing," "awe-inspiring," "dominant," "epic," and "heroic." Each of these words reflects a sense of greatness or grandeur, indicating that the subject in question is truly extraordinary. These synonyms can be used in a variety of contexts, from describing a towering mountain range to a charismatic public figure, conveying a sense of wonder and admiration for the subject at hand.