Many animal costumes tend to look similar, a furry covering and a tail, and may be impossible to tell which animal it represents without the ears. The ears are part of a head covering. So, will the baby leave the ears on and not destroy them by pulling or chewing? Ask yourself this simple question, if the ears must go will the costume look like what it is supposed to look like and in an unambiguous manner? It is a real possibility the ear will not make it through the entire trick or treat outing.
The disc Jockey costume comes with fake headphones. Will the headphones be tolerated by the child? If not, does what is left really say disc jockey?
Most of the baby costumes come with head gear. The real question is will the costume work if it must be altered by having the head gear removed? If not, the baby could wear regular clothing. If a parent pays for a child to be a certain character, and that character is unclear to those who have not seen the entire costume in the first five minutes of wearing, perhaps the money for the costume was not money wisely spent.
Predicting the reaction of a baby to a costume, or to any part of the costume, is a difficult task. Finding out there is a problem on Halloween night while the other children are ready to go out for a night of trick or treating is too late. So, give some thought to what can go wrong prior to Halloween night. Then, prepare in advance. And if it rains there probably will be no trick or treating, so have an alternative place ready just in case.