a silent mouse/ninja.
Sly fox
bell
Cat
he was a sneaky jackrabbit.
Her smile was a sneaky shadow creeping across her face, hiding her true intentions in the darkness.
He is sneaky like a silent mouse
he is a fox
She is a criminal, she is a raccoon
he is a fox
One of the oldest is "sneaky like a fox". You could say "sneaky as the smartest con man".
Old is like an owl but with even better intelligence. this is not a metaphor but a simile. A metaphor for old in a sentence would be
your heart is a black hole. your heart is the the sun.
yes, but it can also be a verb ex. dont be so sneaky (sneaky is a verb in that sentence, cuz the person is doing that) the sneaky fox decapitates a chicken (sneaky is an adjective because it describes what kind of fox)
metaphor {apex}
suspicious ,sly, serpatious