Delibird

It has bad stats, a poor movepool, and a type combo that gives it many weaknesses to common attacks. A 4x weakness to Stealth Rock makes matters even worse, especially seeing as Rapid Spin would have been one of its greater assets. Throughout the UU metagame, you will find that Delibird is easily countered and any job you want it to do will probably be done better by something else. If you are running the Choice sets, ensure that you have solid Rapid Spin or anti-Stealth Rock support to ensure that Delibird can come in and fire off hits. Sadly, even if Smogon were to endorse a NU tier, Delibird still wouldn't be competitively viable. In short, there is almost always a better choice out there than Delibird.