Hi Five Ghost, also spelled as High-Five Ghost, and nicknamed Hi Fives, HFG, or Fives is a main character in Regular Show. Hi Five Ghost is a ghost who works alongside Mordecai and Rigby as a groundskeeper at The Park. Just like Muscle Man, he loves pranking Mordecai and Rigby, but doesn't take it as seriously. Hi Five Ghost made his first debut as a cameo character in the Pilot. He then made his official appearance in "The Power". Hi Five Ghost almost never speaks, but when he does, he was voiced by Jeff Bennett in Season One, and then he was voiced by J.G. Quintel.
Hi Five Ghost is a small, pale ghost. He is semi-transparent as you can see through him, but not completely through. He has basic features, eyes, and a mouth, and also has one hand sticking out of his head. It was revealed in "Go Viral" that Hi Five Ghost has four extra arms, or it is possible that he can spontaneously generate any number of arms that he wants. In "Gut Model," it is seen he can transform into a sphere-shaped shield which can withstand the hot temperatures of frying grease. It is unknown if he has further abilities to morph his body.
He and Muscle Man seem to be best friends, since they are always assigned jobs together. When Muscle Man is in a frame, it is to be assumed that "Fives" is along with him. The two are nearly inseparable, just like Mordecai and his best friend Rigby. Hi Five Ghost only makes fun of Mordecai or Rigby when Muscle Man is around. In episode "Gut Model", he officially told Muscle Man that he was his bestest friend.
Hi Five Ghost is friends with Mordecai and Rigby, as shown in "Muscle Woman", but other times Hi Five Ghost is in conflict with Mordecai an Rigby, namely because Muscle Man does this as well, as shown in "My Mom". Mordecai and Rigby have never been in an argument with only Hi Five Ghost, only with Muscle Man and Hi Five Ghost. In "Gut Model", Hi Five Ghost was happy to be paired up with Mordecai and Rigby. Hi Five Ghost seems to be the only character to respect Mordecai and Rigby other than Pops.
Skips challenged Hi Five Ghost to an arm wrestling match in "Over the Top." Later on, Skips And Hi Five Ghost pranked the rival park in "Prankless."
In the episode, "See You There," it is revealed that Hi Five Ghost has a brother and rival whose name is Low Five Ghost. Low Five Ghost looks almost identical to his brother, except that Low Five Ghost has a bit of scruff where his "chin" would be, and wears teal sunglasses. His personality is that of a wild teenager, similar to Rigby. Low Five Ghost has the power to turn non-ghosts into ghosts.
In "See You There," Hi Five Ghost's father is also introduced. He remains unnamed except for "Dad" to Hi Five and Low Five. Their father is also the only one in the Ghost family who knows how to change people from ghosts back into their normal form. Hi Five Ghost and Low Five Ghost look like their dad except their dad has a beard where his "chin" would be.
- Hi Five (or High Five)
- Hi Fives (or High Fives)
- Hi Five Ghost
- Undead - Even though it is unknown if he was born alive, Hi Five is shown to be a ghost and lives and interacts with others, even though he's a ghost.
- Trumpet Player - In "This Is My Jam", it is shown that Hi Five Ghost can play the trumpet, even though Muscle Man blows into the mouth piece.
- Loud Laughs - Even though Hi Five is usually silent, he has a very loud laugh, which was shown in "The Night Owl".
- Levitation- Hi Five Ghost can float instead of walk and never gets tired of doing it.
- Intangibility - As revealed by his brother, they can go through solid walls and objects. He has demonstrated this ability in numerous episodes, such as "Prankless."
- Ability to Form a Shield - In "Gut Model," it was revealed that Hi Five Ghost can turn into a spherical shield.
- Pranks - He is a master pranker alongside Muscle Man.
- Hot Wiring - He can also hot-wire a car to go very fast, as seen in the episode "My Mom."
- Speech Giver - He eased Muscle Man's feelings when he thought nobody cared he was leaving in "Gut Model" by giving a speech that it was just bad timing, and to get over it.
- Hi Five Ghost's Father ("See You There")
- Muscle Man and Hi Five Ghost's Trailer (Several episodes)
- Muscle Man and Hi Five Ghost's TV ("Rage Against the TV")
- Goof: Despite his name, Hi Five Ghost is shown to only have four fingers. Though, his four other hands have five fingers. His name may reference the 'high-five' position his main hand is in.
- The credits credited J.G. Quintel, Mordecai's voice actor, for voicing him in "Just Set Up the Chairs" and "Rigby's Body", even though Jeff Bennett voiced him. Though, Quintel voices him in season two and onward.
- Despite having the usual traits attributed to a ghost, such as levitation and transparency, Hi-Five can be touched, as evidenced by his usual hand slaps with Muscleman. He can also get hurt, as he sustained some bruises in the episode "Rage Against the TV."
- In "See You There", Low Five Ghost stated that ghosts can't be touched by anything except by another ghost, but Hi Five Ghost usually is seen hi five-ing with Muscleman.
- Hi Five Ghost has the second most family members actually seen in the series (Being his dad and brother; both in "See You There"). Benson has the most family members while Rigby, Muscle Man, Mordecai and Pops have one (Pops having his father, Mr. Maellard, Rigby having his brother, "Don", Muscle Man having his father muscle dad, and Benson having his mom, dad, and sister and Mordecai having his Uncle Steve). Skips has none.
- He can also change color; sometimes he is green and sometimes he's white.
- In "Exit 9B", he was shown as a baby ghost in the past, with what appears to be a human mother holding him. He was also shown as a high school student, with shaggy brown hair and a green army-style jacket.
- In "Exit 9B," identity files about him show his height to be 5'7". In the same files, his weight is listed as N/A, which may indicate he weighs nothing at all.
- He, Pops, and Thomas are the only workers at the park to never have had a love interest.
- Hi Five Ghost can be considered the quietest character in the series as he appeared in 51 episodes, but only spoke in 18 episodes and, therefore, did not speak in 33 episodes.
- In the episode "Trucker Hall of Fame," Hi Five Ghost is seen crying a lot when he's at a funeral, which is why Benson wants Mordecai and Rigby go with Muscle Man because Hi Five Ghost doesn't handle these sort of things well.
- As shown in Exit 9B, Hi Five Ghost used to serve in the British Army.
- He was talking to a girl throughout the whole rollerblading area in Bald Spot.
- In "Guy's Night," it's revealed that he drank a gallon of creamed corn for a tote bag.
- It was revealed in Exit 9B that when Hi Five Ghost signs things he spells it Hi 5 Ghost.