Why did Satan enter the serpent rather than another creature?

Answer 1

Satan was still noticed and recognised and revealed fully in New testament. Satan was the Old serpent meaning from the garden who is the great dragon. Rev 12:9 and 20:2 is clear there. rev 20:2 And he laid hold on the dragon, that OLD SERPENT, which IS THE DEVIL, and Satan, and bound him a thousand years ..(emphasis added)

rev 12:9 And the great dragon was cast out, that old SERPENT, called the Devil, and Satan, which deceiveth the whole world: he was cast out into the earth, and his angels were cast out with him.

So the serpent which was an actual serpent was the Devil in the form of the serpent, which many believe that Satan entered into him like he did with Judas at the sop.

Answer 2

The story in Genesis is about the serpent, not Satan. There is no suggestion anywhere that Satan was even involved. In fact, scholars say that the concept of Satan did not enter Judaism until after the Babylonian Exile. As to why the serpent was the evil player in the story of Adam and Eve, snakes are almost universally reviled and are frequently portrayed as evil in primitive stories.
If the serpent had been Satan in disguise, then The Bible tells us he was able to fool God, who said to the serpent, or snake, that he would henceforth crawl on his belly (Genesis 3:14). Most Christians would not accept that God could so easily be fooled, so the serpent and Satan are entirely different concepts, in spite of the Book of Revelation.

Answer 3

In Christian theology, Satan chose to enter the serpent because it was one of the creatures God had given Adam dominion over. By tempting Adam and Eve through the serpent, Satan sought to undermine God's relationship with humanity and deceive them into disobeying God's command.