Listen carefully: I have given you authority [that you now possess] to tread on serpents and scorpions, and [the ability to exercise authority] over all the power of the enemy (Satan); and nothing will [in any way] harm you. Luke 10:19,20 Holy Bible Amplified Version
I do not believe Christ is referring to the creature but to those who represent the creatures.
So for example, the serpent represents satan while the scorpions represent those whose tongues and hands represent wicked ones out to do you harm.
The harm mentioned is not referring to physical harm but rather spiritual harm. They are out to poison your relationship with Jehovah, Jesus and the Holy Spirit.
The wicked ones are out to kill your love for them.
The authority is given by Christ in His name and the power comes through the Holy Spirit.
Because Jesus is the Supreme Power satan and his minions do not have the power to harm us (they can tempt us but never physically, mentally, nor spiritually harm us).
They are constantly around us which is why it is so important to stay close to Christ.
If we stray away from Jesus we are easy pickings for satan and his henchmen. Joseph a son of Jehovah
Prayer: Thank you Jesus Hamelech ( Jesus my Lord King ) for blessing this dedicated servant of Your with the necessary tools to defend myself successfully against the serpents and scorpions that come my way through the day. I glorify You in Your majestic name. Amen
May you be blessed with peace and joy every day.