redman
A 1972 tokusatsu series, very similar to Ultraman where the titular character grows in size to fight monsters. Created by Tsuburaya Productions, it aired as a 5-minute segment of the variety show Ohayou! Kodomo Show, with 138 episodes in total.
The show was considered a cult classic among some tokusatsu fans for the appallingly low budget production, monster costumes recycled from Tsuburaya's previous low budget short series Ultra Fight and non-existent plot for every episode. Other than its titular character being recognized as a proposed design for the original Ultraman TV series, the Redman character is also known by fans as a "serial killer" due to the nature of the show, which involves the hero beating up and killing the monster for no reason, sometimes in gruesome fashion.