Here are some English translations and illustrations; to share here I chose the version in verse by Oliver Herford, with an illustration by Francis Barlow. In some versions of the fable, the focus is on providing a warning to the other shepherds not be fooled, but in Herford, the emphasis is on warning the sheep to beware of wolves in disguise.
THE WOLF IN SHEEP'S CLOTHING
A wicked Wolf once donned the skin
Of a dead Sheep and so got in
Among the flock, deceiving by
His artifice the shepherd's eye.
All day, secure in his disguise,
He watched his prey with gleaming eyes
And ever growing appetite;
But fate willed otherwise. That night
The careful shepherd, counting o'er
His sheep, discovered one sheep more
Than he possessed, and, looking through
The flock again, he caught and slew
The Wolf and hung him to a tree,
That any passing Sheep might see,
And, having seen, might warn the rest,
"A Wolf's a Wolf, howe'er he's dress'd."