Are there any items which raise your maximum stats?

While poking about on the Don't Starve Wiki, I've seen a number of items that will lower the maximum stats for things like health or sanity. (e.g. The Meat Effigy lowering maximum health)

Are there any items or companions that cause your maximum health/hunger/sanity to increase?

There is only one character that can raise its maximum stats: WX-78, the robot. It can eat Gears, which upgrades its maximum health, hunger, and sanity with each Gear consumed. It can consume a maximum of 15 gears, to get 400 health, 200 hunger, and 300 sanity. (The bonus is 20 health, ~6.66 hunger, and ~13.33 sanity per gear, rounded up.)

WX-78 needs this pretty badly, because it starts with below-normal stats.