Tubby Custard is a pinkish drink, and the main drink of the Teletubbies. It is made by the Tubby Custard Machine.
Custards are the main point of the White Tubbie's quest, and the reason of the Teletubbies's infection.
It's a bowl filled with a pink substance, and drank with a straw. It can also be eaten like soup and with a spoon, instead.
Collecting the custards is the main activity of the saga. The point is to collect all of the custards that are located on the area, and the complete collection allows to win.
The day before The Massacre, the teletubbies were passing a normal day, but the custard of Tinky Winky seemed to be somewhat infected. This affected his mind and incited him to kill his friends.
After this incident, all of the custards seems to be infected and scattered around many locations. The infected custards could be the reason of the teletubbies's conditions. The reasons behind the infection and the dispersions are caused by Noo-Noo who infected the custard.