The stars and planets represent God’s creation of the universe. (Genesis 1)
The tree is the tree of knowledge in the Garden of Eden. Adam and Eve sinned for the first time when they disobeyed God and ate the fruit from it. (Genesis 3:3)
The serpent represents Satan, who tempted Adam and Eve, and tempts us, to sin. (Genesis 3)
The dolphin symbolizes resurrection and salvation. The legend is that carries the souls of the faithful departed across the waters to eternal life.