From Wikipedia:
The Loogaroo is a woman, who is in league with the devil. She will have magical abilities only if she gives the devil blood every night.

The Loogaroo can leave its own skin (by going to a Devil Tree - unsure if that is a specific tree or type of tree) and turn into a flame or blue ball of bright light that haunts the night searching for blood to meet the terms of her deal. After it has collected enough blood it can return to its skin and retake human form.

This creature is apparently compulsive and must stop to count grains of sand spread upon the ground. So, a defence against it was to leave a pile of rice or sand near your front door. Hopefully, the creature would take so long to count it all that the sun would eventually return with the coming of morning. By that time the Loogaroo would have to return to its skin without making an attack.

The Loogaroo is an example of how a vampire belief can result from a combination of beliefs, here a mixture of French and African Vodu or voodoo. The term Loogaroo possibly comes from the French mythological creature called the Loup-garou, a type of werewolf and is common in the Culture of Mauritius. However, the stories of the Loogaroo are widespread through the Caribbean Islands and Louisiana in the USA.