|Home World||The Nightmare Realm|
|DNA source||Ghost Brandon|
|Alternate Counterparts||Ghost Brandon|
|Powers and Abilities|
Dark Energy Manipulation
|First Appearance||Theater Terror|
Big Boo takes the appearance of a blue being with four layers of skins; the top layer being his head, the second being his chest, the third being his waist and the bottom layer being his tail. He has claws on his arms and no visible mouth. The Omnitrix Symbol is on his chest.
Powers and Abilities
Big Boo has the ability of flight as well as invisibility. He can also remove dark energy from above his skin and use it as a way of extracting nightmares from enemies and using it against them. Big Boo can also use his claws as a slash attack.
Big Boo can be weakened by large amounts of light and certain chemicals which can cancels out his invisibility. Certain energy frequencies can also cancel out his phasing abilities as seen in Brawl.
- Theater Terror (First Appearance)
- The Conqueror
- The Forest
- Bad Luck
- Ocean Land
- The Nightmare Realm
- He is the first ghost and flight alien in Brandon 10.
- In The Original Series, Big Boo was used after his had lost control to Ghost Brandon which made him the 11th alien in The Original Ten.
- However, this failed to make much sense so it was later changed so that Big Boo was still in the Original Ten and Twisty was made the first additional alien.
- Big Boo is the only alien apart of The Original Ten who didn't get a short.