October 31 is celebrated by many people with trick-or-treating or going to a party. Google is wishing users a happy Halloween with a Scooby Doo-themed doodle this Sunday.

The interactive drawing greets users with five different colorful drawings from Scooby Doo, a Hanna-Barbera cartoon. It features a haunted motif, including costumed kids, ghosts and ghouls, and jack-o-lanterns. The doodle tells its own mini-story. Letters from the word "Google" are scattered throughout the five pictures, and users are invited to help find the mixed-up letters.

The animated series Scooby Doo has been on the air since 1969. Sleuths Fred, Daphne, Velma, and Shaggy travel around in the Mystery Machine solving mysteries that are often caused by some kind of supernatural creature.

Google posts different doodles frequently. Earlier this month, the search site honored the 93rd birthday of legendary jazz trumpeter, Dizzy Gillespie. A few days prior to that, Google remembered former Beatle John Lennon on his would-be 70th birthday. This doodle featured a snippet of the song iconic song, "Imagine," and the wind blew stems off of a dandelion to form the name of the search engine.

But Google doesn't just remember those who have died, rather it commemorates others who have reached milestones as well. Earlier this fall, Google paid tribute to the 50th anniversary of the "The Flintstones" with a doodle. Before that, it wished the Pac-Man game a happy 30th birthday with a full, playable game on the main search page. Google has kept this Pac-Man doodle online due to its overwhelming popularity.

A simple pastel drawing of a cake marked Google's own 12th birthday in September.