(literally) between a dog and a wolf / (by extension, idiomatic) at dusk, at twilight; gloaming / (photography) golden hour (used in same technical sense for “good photographic light at twilight”)

wolf in sheep's clothing

speak of the devil (an expression sometimes used when a person mentioned in the current conversation happens to arrive on the scene)

(simile, impersonal) to be dark to the point where one can't see; to be pitch-dark

man is a wolf to man

(figuratively) to have the wolf by the ear (to be in a dangerous situation from which one cannot disengage, but in which one cannot safely remain)

(figuratively) to walk into the lion's den

speak of the devil and he shall appear

magnifying glass / loupe / wen (a cyst on the skin) / burl, a growth on the side of a tree / laziness

plural of loupe