Over its many lifetimes, Futurama has evolved from a science fiction riff on sitcom tropes into something more emotionally resonant. In the process, a lot of the show's basic parody characters and concepts have grown to become more idiosyncratic and character-driven. This is particularly true for Kif Kroker, who began as a straightforward riff on Leonard Nimoy's iconic Spock -- but has gained a fuller life as his own character.
Source：https://www.cbr.com/futurama-kif-toughest-character/
