Lasius's page

Keep in mind that the Natural Armor of the Lizardfolk won't stack with that granted by the Mutagen. Beyond that, they're a fine choice, as they save you from needing to ever take Feral Mutagen in the first place. Also their stat spread is hilariously good.

I'd honestly pass over Infusion unless your party has no dedicated arcane caster.

What discoveries would you recommend for the early levels then. The greater/grand/true mutagen line as well as crippling strike are no-brainers, but it seems to me that a melee alchemist doesn't need as many discoveries as the bomber.

If you have extra arms (not feet, they have separate natural attacks) then you'll get more claws. Otherwise, no, Feral Mutagen is wasted.

The gamebreaker choice for the Vivi-Beast is the Ragebred Skinwalker. Two of their abilities are a Gore attack and a pair of Hoof attacks. By taking Extra Feature as your first-level feat (so you can get both of those at once) and then Feral Mutagen as your second-level Discovery, you can have six natural attacks at level two, four of them primary attacks.

Fair warning, your GM may hate you for this.

Thanks for this tip, but I guess I won't try this with my GM. I think I'll go lizardfolk instead, so that I have natural attacks+sneak attack even when I have no mutagen. Then I can get infusion early. The natural armor doesn't hurt either.

Vivi + Beastmorph tends to be the go-to. Keep in mind that you are not restricted to one Mutagen per day; the restriction is that you can only have one Mutagen brewed at a time. Take advantage of this: a short break can set you up for the next encounter.

Thanks for the tip. I'll probably go with that.

I was also wondering, if I play a race that already gets a bite and claw attacks, would feral mutagen upgrade them, or could I get two additional claw attacks for my feet?

I was planning on trying an alchemist for the first time and liked the vivisectionist. But I'd also like to have a second archetype in the mix, for a tribal witch doctor themed alchemist.

But what would be more effective?

Beastmorph to get a fly speed, better senses and later pounce, grab and more and be a generally bigger meelee threat.

Or preservationist, to not be useless when no mutagen is available and to power the vivisectionist's sneak attack with cheap flankers that can eat the AoOs. A tumor familiar lobbing these with infusion could even cut down on the action economy.

I am very much on the fence here and both would fit to the concept I have in mind.