It could spread some unknown disease to the other organisms, it could take all of the food that the other organisms need to survive, it could eat the organisms, it could destroy the organisms' surrounding environment.
Answer:
A deletion mutation can remove a single nucleotide, or entire sequences of nucleotides. ... If three or more nucleotides are lost in a gene, entire amino acids can be missing from protein created which can have serious functional effect.
Desert biomes would benefit them if they can store water.
We can't answer that question because you have not provided us with a picture. Sorry
