Brainbox

4 clues
Mastermind
Clever clogs
Clever person
Skull — clever clogs
Similar answers:
Abrain
Abrainandapenis
Abrainchallenge
Abrainof
Addledbrains
Algebrai
Algebraic
Algebraiquation
Anobrainer
Artificialbrain
Badbrains
Bassbraille
Bbrain
Birdbrain
Birdbrained
Birdbrains
Blurredbrain
Braid
Braided
Braidedhair