"Electric Zoo" is a techno-electronic song heard in the episode "Krab Borg." Mr. Krabs was listening to it while counting his money, to great enjoyment. He seemed to love the song, as he asked the radio station to play it again. It's also the episode's title card music.
The song's title is said by a radio DJ. Despite the title being "Electric Zoo," Mr. Krabs basically calls it "The one that goes Beep boo-doo bop boo-doo beep", making SpongeBob confused because, only hearing him say his misunderstood title, he thinks that Mr. Krabs is a robot.
The song was composed by series writer/executive producer Paul Tibbitt.
The song solely uses instruments.
An announcer on the radio said the song's name before it came on, but Mr. Krabs did not know its name when he was asking the radio station to play it again. Though, it is possible he wasn't fully paying attention or that he may have forgotten the title of the song. He may have gotten hooked to the song, only after it started playing.
There are other songs in real life that are known as electric zoo, possibly influenced by this song.