The Lamuellans were the humanoid inhabitants of the planet Lamuella. They were a fairly primitive race, and they had no idea about other planets until Arthur Dent arrived on the planet. They adopted him into their tribe, helped him by healing his injuries as best they could and gave him a hut to live in. He then made sandwiches for them.
In some versions, he also had an apprentice who made sandwiches for the village after he had left.
In the migration season, they hunted Perfectly Normal Beasts for their meat. When Arthur Dent arrived on the planet, he made sandwiches for them out of the meat. They also used the droppings of Pikka Birds to fertilise their crops.