Druid (Grassland/Moon) 9, Cleric (Life/Arcana) 1.
All the cantrips, all the best healing, invis/haste for sprucing up WS, tonnes of handy auto-prepared spells for any eventuality that WS can't handle. Flying forms/CR3 forms. A bit of slot regen, for at worst, best goodberries (40pts per lvl 1 slot, 5 slots to gain a day) or bless spamming. Great stealth with Pass without Trace, for you and your summons/party. Lots of summons. Heaps of prepared spell versatility with cleric subbing in for druid equivalents, so you know a tonne of higher level druid stuff each day. Lowish level build that keeps getting better the more druid it gets. Feat, stat, cantrip as wanted, with a basic 1.5x+ caster as standard with all those handy slots, but can go combat'y as well in multiple different ways. Add monk 1 for Wis armour in WS if you want, but you're already not bad even in normal form (GFS/Shillelagh/Haste), all run off Wis. MI Hex in if you want, but you don't really need any warlock cast-offs by this point.
or
Rogue (Thief/Assassin) 17, Cleric (Knowledge/Trickery) 3
Auto-10 on any of the skills you want. Spellcasting and stealth-mastery (PwT) before or after multi-turn-stab-killing. Buddy up with a sneaky partner when needed, or divine out a shadow clone to help with SA output.