Rarely used; may refer to a specific type of animal.
El caudatremula de la serpiente se movía nerviosamente mientras acechaba a su presa.
The tremulous tail of the snake moved nervously as it stalked its prey.
El pez tenía una caudatremula que se movía de manera peculiar cuando nadaba.
The fish had a tremulous tail that moved peculiarly when it swam.