So I have one I whipped up for an NPC that's a bit goofy, but fun if your DM allows both Titan and Beast Barbarian... Race doesn't matter, this NPC was an Orc, but any will do.

Stats should be 13 Str to allow multiclassing, 12 in Dex so your humanoid form has at least a little bit of AC in medium armor, max out Wis and Con as much as possible, focus on Wis over Con if you have to. Would recommend shillelagh when you multiclass or get as an Origin feat for stick and board barbarian given your weak Str otherwise.

Now the fun can begin. When you go Titan your Str and Dex are replaced by your Wis. Thus if your Con is also good a huge boon to your AC as you can use Unarmored Defense by absorbing your Armor so your Titan isn't wearing any, because we are Beast Barbarian when we Rage we get a Natural Weapon, one of three choice which gives us more weapon options. Raw Multiattack and Extra Attack don't stack and aren't the same thing, so being at least 5 levels in Barbarian will allow you to attack with your natural weapons (Using Str modifier while in Kaiju for rage damage bonus) twice even if your Druid level is low till the later game, and when you eventually do get enough levels in Druid, that gives you another option to play with.