Dark Dreams of Furiae - a new module for NWN:EE! Buy now
You need a tank? Call Aerie!
Do golems hurt your feellings (and flesh too)? Do demons and dragons offend you? And even Demogorgon himself (well, his avatar actually) takes you pocket money? Say all of them NO! But it's even better let Aerie say them NO!
Equip Aerie with 'Cloak of the Sewers', 'Defender of Easthaven' (in shield slot) and the 'Ring of Gaxx' (for example), add some situational magical defenses, turn into a RAT and go forward - to tanking! For justice! Squeak!
But if seriously, ANY character capable of holding in hands (or rather,in LEFT hand, i.e. shield slot) 'Defender of Easthaven' and turning into a rat by 'Cloak of the Sewers', is able to withstand any amount of physical damage - all physical defenses are at 100%! Its something like a IWD druid in water elemental form (plus 'Armor of Faith' spell, for example), but a little more universal and available at almost any party level and not dispellable.