Rasin and Lakasei are a pair of alien brothers that serve as henchmen for Tullece and are villains from the Dragon Ball Z movie, The Tree of Might.
Next to nothing is known about Rasin and Lakasei's past, except for the fact that they were recruited by Tullece at some point.
After deciding Earth was able to sustain the Tree of Life, Rasin & Lakasei, along with their cohorts, Amond, Daizu, and Cacao, accompanied Tullece to the planet, so as to plant the tree. The duo, along with the others, fought against the Z Fighters after they attempted to put an end to Tullece's plans and won rather easily. They later took on Son Goku, only to be meet their end after he used his Kaio-ken technique.
As well as all the basic powers of most of the other Dragon Ball series characters, Rasin and Lakasei have the power to combine into one being, then separate at will.