A she-wolf in a barren desert with no thicket. ذِيبَةُ قُفٍّ مَا لهَا غَمِيسُ‏.‏

  The barren desert is a rough, uneven piece of land, and the thicket is a valley with dense vegetation. This proverb is used to describe someone who openly displays hostility and hostility.
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The closest English equivalents to this proverb are expressions that denote open hostility or someone who doesn't hide their enmity, such as:
“He wears his hostility openly.”
Meaning: He displays his hostility openly.
“An open enemy is better than a false friend.”
Meaning: A true enemy is better than a false friend.
This is close in meaning to openly declare one's opposition and not conceal it.
“What you see is what you get.”
Meaning: He doesn't hide his true nature or stance.
It can sometimes be used for someone who clearly expresses their position.
“He doesn’t hide his claws.”
Meaning: He doesn't hide his claws, i.e., he doesn't hide his hostility or ferocity.
And the closest expression to the spirit of the Arabic proverb is:
“He makes no secret of his enmity.”
“He doesn't hide his enmity.”
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القُفُّ‏:‏ ما غَلُظ من الأرض، والغَمِيس‏:‏ الوادي فيه شجر ملتفّ‏.‏
يضرب لمن جاهر بالعداوة وأظهر المناوأة‏.‏