from a post on minmaxboards.ComRevisiting an old chestnut, the Druid with a dip in Monk. However, it looks like it may be quite a bit more viable in 5e.
1. Druid 1: Druidic, Spellcasting
2. Druid 2: Wild Shape, Druidic Circle (Moon)
3. Monk 1: Martial Arts, Unarmored Defense
Now, this build is predicated on a couple of understandings:
1. Using a natural weapon constitutes an unarmed strike. This is supported by the text of Alter Self, which affirms that when you use the spell to give yourself natural weapons, the attacks you make with those weapons count as unarmed strikes.
2. Martial arts says that you CAN roll a d4 in place of the normal damage of your unarmed strike or monk weapon; it doesn't say you must. Obviously, most low-level monks will prefer to roll the die for their weapon, if using a monk weapon.
Given these understandings, the build's straightforward:
1. Wild Shape into brown bear
2. Attack with the brown bear's claw-bite combo.
3. Since you're attacking unarmed, make an additional attack with the claws. (Choosing to employ their damage rather than your d4.)
All in all, it's a hard-hitting package for level 3. Unarmored Defense isn't going to give you a spectacular armor class, but it'll at least be an improvement over the 11 that the bear normally has. Once you hit 20 Wisdom, you'll have a 16 without needing to use spell slots on Barkskin.
One of my players sent me a link to this character build post. I wanted to know if you would allow this in your game if you were the DM. I have my thoughts, but I want to see what you folks think before I post my own thoughts.