When it comes to describing someone who constantly complains and makes excuses for their failures, the term "whiny loser" is often used. However, there are many other synonyms that can be used to describe someone with a similarly negative demeanor. One could describe such an individual as a "crybaby", or a "sore loser". Other terms such as "mopey", "petulant", or "spoiled" could be used as well. Ultimately, the key is to find a word or phrase that accurately captures the essence of a person's behavior, without resorting to name calling or insults.