McTavish is an astronaut and commanding officer on Space Platform Galileo. McTavish's military rank is Lieutenant Commander. His primary duty is to serve as chief engineering officer and monitor power sources. During an incursion, McTavish was the second witness to report sighting of The Creature. When the Ghostbusters arrived, McTavish was ordered to escort the team to engineering, where the entity was last seen.
After their encounter, the Ghostbusters and McTavish returned to the Bridge. He bypassed engineering and tapped the station into the four hour emergency reserve in an effort to lure The Creature out into the open. McTavish's next task was to don a space suit and manually disconnect the solar panels located on the exterior of the station. The Ghostbusters then ambushed the Creature and trapped it.
- McTavish looks to be a spoof of Montgomery Scott also known as Scotty. Most likely based on the first film version.
- McTavish notes Egon Spengler reminds him of an old shipmate with pointy ears, implicitly referring to Mr. Spock from the Star Trek franchise.
- One of the Leprechaun's victims in the Extreme Ghostbusters episode "The Luck of the Irish" is also named McTavish.