Taco Comet is the 6th episode of Uncle Grandpa season 2, and the 58th episode overall of the series.
Uncle Grandpa and the gang go undercover in order to get a taste of a greatly sought-after treat.
The RV is driving fast in space and Mr. Gus is panicking Uncle Grandpa to slow down the RV but Uncle Grandpa says he can't. Pizza Steve walks into the cockpit of the RV and asks why they're in outer space because the satellite reception is awful, Uncle Grandpa states that he's looking for the Taco Comet that arrived at Earth 8,000 years ago when it brought tacos to Earth and changed dinner forever. Uncle Grandpa states that it has returned to orbit the galaxy and he proceeds to have his mouth water up, Pizza Steve thinks that Uncle Grandpa is doing all of this so he can eat the comet and Uncle Grandpa corrects him. Belly Bag says that eating the comet is Uncle Grandpa's life goal ever since he figured out what a life goal is, Mr. Gus calls Uncle Grandpa back to the cockpit and informs Uncle Grandpa about the leafy green things outside, Uncle Grandpa gets excited and steps on the gas and he approaches the comet. Uncle Grandpa assigns everyone roles around the RV to ensure Uncle Grandpa eats the Taco Comet, while Uncle Grandpa reaches the comet Pizza Steve wonders how he's going to eat it, the Uncle Grandpa farts and pushes the comet to fall down to Earth. The RV lands back down to Earth and Uncle Grandpa is looking for the Taco Comet, he finds it and right as he's about to eat it the army helicopters pick it up and they take it away.
Uncle Grandpa is crying that they took the comet away but Mr. Gus says that they could just follow the meat droppings to find out where they took it, so they decide to follow the trail. Uncle Grandpa sees that they took the comet into some shopping mall but Mr. Gus states that they can't go in there because it's actually Area 51 and states that there is no way they're getting inside there. Pizza Steve has and idea and proceeds to retrieve some items from Bely Bag to disguise themselves as aliens. The guys walk past the gate and the guard tells them that they're suppose to be in the base, Pizza Steve says that it was a nice day to enjoy the sun, the guard agrees with him and lets them inside the base. Uncle Grandpa follows the trail to a hangar and finds out it's locked, so he drops an anvil on himself to make him flat and he asks Mr. Gus to slide him under the door, Uncle Grandpa smashes the door's window with the anvil from the inside and pulls out a paperclip which he uses to open the door. The guys found the Taco Comet inside a room with scientists performing tests on it, Uncle Grandpa worries that they're going to eat the Taco Comet and that there won't be any left for him, then an Orange Alien wants to help them out only if they can get him out from his prison.
The Alien is happy for his freedom and he proceeds to release all the other aliens, some Grey Aliens decide to tear the place apart and they proceed to go inside the room with the Taco Comet to terrorize the scientists. The guys wonder how will they get the comet out and then Tiger bursts through the wall with a tank and they escape with the Taco Comet. Area 51 is being destroyed by all the released aliens and they break through the gate with the tank, the guard is questioning where they're going and Uncle Grandpa wears some fake antennas saying that they're taking the taco out for a Sunday Drive, the guard then says that it's a beautiful day and the Orange Alien threatens him. Once in a clear open space Uncle Grandpa can finally eat the Taco Comet, he puts on some bigger teeth and before he can take a bite, a UFO drops in with two smart looking Pink Aliens clamming to be Universal Guardians and they tell Uncle Grandpa to not eat the comet so they can take it with them to release it back into space. Uncle Grandpa tells them that they can take the comet back, they get back into the UFO and they put the taco in a doggie bag and they take off. Even though he will never taste the comet there's always the Hamburger Meteor Shower happing next month, in space the "Universal Guardians" are eating the comet clamming the guys to be suckers.
- Eating the Taco Comet is Uncle Grandpa's life goal.
- The small bluish-grey aliens are a reference to an alleged alien species called the Greys or Zeta Retuculians.