Bicolour Blenny

Snapshot: Its sleek, elongated body is adorned in a striking blue hue on top and a vibrant orange-yellow below. It has large, bulging eyes, lending it an almost alien-like appearance.
 
Other tidbits: Can grow up to 11cm or so. Native to the tropical waters of the Indo-Pacific region. With rows of tiny comb-like teeth, they're also the ultimate algae-stripping machines, tirelessly scrubbing corals and rocks clean.
 
Bare bones must know: Any tank will do, but this species thrives in setups with plenty of live rock. Thick, sandy substrate.