look exactly alike
Él y su hermano son como dos gotas de agua.
He and his brother are like two peas in a pod.
Las hermanas gemelas son como dos gotas de agua.
The twin sisters are like two peas in a pod.
Su hermano mayor y él son como dos gotas de agua.
He and his older brother are like two peas in a pod.
They are like two peas in a pod.