Byouz

Byouz (ビョーズ) is an enemy in Mega Man V. Byouz can extend its head and stays exclusively to the ceiling, to the point that it will even "fall" up if it walks off the edge. It is only seen in Saturn's stage. It has a large, non-lethal spike on its head.

Etymology
Its name is probably a combination of Japanese words, "byou" (鋲, tack) and "zu" (頭, head).

Similar enemies

 * Nobita