As this is supposed to be a RPG, I think it would be cool if we could choose any ingame creature as our avatar, so which would you choose? Your character would have perks or bonuses related to that particular creature.

Bloatfly = Critical long range damage, additional damage given on explosion.
Deathclaw - critical melee damage
Radstag - head butt damage
Yao guai - Fist damage
Mirelurk - ranged damage
molerat - no particular damage except for a bit of poison and also being extra annoying
Radscorpion - extra damage when in stealth mode
Mongrel - Bite damage and poop damage - the enemy has to change their shoes after stepping in it.
Brahmin - peaceful warrior, diffuses potential fights with diplomatic words in brahmin language.
Radgull - pecking eyes out damage.

Your partner (Norah or Nate) can either be the same creature or a different one, and baby Shaun looks like a mutation between the two. Codsworth hates him, refers to him as the "spawn of the devil" and doesn't ask you where he is when you come back out of the vault. When you later meet Shaun at the institute it's a bit surreal and you start to wonder whether it was worth looking for him at all.