Wolfpack (sometimes incorrectly referred as Wolf Pac) is originally played in Wolfenstein 3D (DOS). The secret level throws you into a 3D Pacman level, so the music is appropriately cartoony.
The name is verified by in-game jukebox.
The song plays at approximately 178 beats per minute, and is in the key of D♭ major. The song plays in the 4/4 swing time. The main riff of the song is a slowed-down version of the starting music in Pac-Man (ARC) (one extra note added to the end of each bar). The lead instrument is played on an organ, with an accompanying piano, mostly playing with flattened 5ths to sound like 7th chords. The walking bassline is played by either an acoustic or electric bass. There are some nice eighth-note triplets thrown into the song from the bass. The organ also plays a few grace notes, adding to the jazzy nature of the song.
Wolfenstein 3D (DOS)
It plays as the music for the secret level of episode Die, Fuhrer, Die! (E3M10)
Wolf Pac is track 27 in the game's data. Its title in the IMF meta data is "PACMAN". This song is not in the shareware released of Wolfenstein 3D. The title "Wolfpack" is a play-on-words of "wolf pack" and "pacman".
Wolfenstein 3D (WEB)
It also plays on E3M10. This version is almost identical to the original.