Beastie

FreeBSD Beastie is the mascot of the FreeBSD operating system. It's a small, red, cartoon devil with horns, a trident (or pitchfork), and sneakers. The name "Beastie" is a play on the acronym BSD, which stands for Berkeley Software Distribution, the Unix variant from which FreeBSD is derived.

Official logo in www.freebsd.org

Background

Appearance: Beastie looks mischievous but friendly. He’s not meant to be a symbol of evil — the devil imagery comes from the Unix tradition of "daemon" processes, which are background services in Unix-like systems.

History: The character predates FreeBSD itself and was originally used as a generic mascot for BSD Unix. It was popularized in the early BSD community and adopted by FreeBSD. Many folks have asked about the BSD daemon's name. Contrary to a myth first started by some advertising droid at Walnut Creek, the daemon's name is NOT Chuck. He is very proud of the fact that he does not have a name, he is just the BSD daemon. If you insist on a name, call him beastie. Source: https://www.mckusick.com/beastie/index.html 

Name: “Beastie” is a phonetic play on “BSD” (B-S-D → Be-as-tie).

Daemon vs. Demon

The term "daemon" (used in computing) comes from Greek mythology and refers to a guiding spirit — not a demon in the religious sense. That’s why Beastie represents system daemons (background services) in a friendly way.

Modern Use

While Beastie is still an iconic figure, some modern FreeBSD branding materials (especially in corporate or formal settings) may use a more neutral logo (like the stylized "F" orb) instead of the devil mascot to avoid misunderstanding or controversy.

Some other logo variants

Nice one :-) It is from https://www.freebsd.org/art/

BSD Daemon from https://en.wikipedia.org/wiki/BSD_Daemon