Mágū is usually depicted as a lovely woman with long nails accompanied by a deer, and carrying a peach, or basket of peaches. The peaches grant longevity, and a drink of her famous elixir is said to bestow perpetual youth.

She is a Taoist goddess, and a symbolic protector of woman.

Her name translates as 'hemp lady', or 'hemp priestess'. 

Many tales are told of her, the most famous being about her long nails. Once, while at a banquet, her host became obsessed with the idea of how wonderful it would be to have his back scratched by her long nails. For these unseemly thoughts, the host was thrashed by an invisible whip. 'As delightful as being scratched by Mágū'  is a common expression of randy delight.

There were once temples to Mágū in China, and there are mountains and caves named after her. She is seen as an auspicious goddess, and drawings of her are often given as birthday presents, or to married couples on important anniversaries. 

To summarize the interesting Wikipedia article regarding Magu and Cannabis:

• Magu appears to be connected with early Daoist religious usage of cannabis
• Magu was goddess of Shandong’s sacred Mount Tai, where cannabis was grown
• Early Daoist Yangi Xi (330-386 CE) was "aided almost certainly by cannabis in writing the Shangqing scriptures during nightly visitations by Daoist immortals. The scriptures are known as "The True Text of the Great Dong."
• Historian and sinologist Joseph Needham concludes:

“Thus all in all there is much reason for thinking that the ancient Taoists experimented systematically with hallucinogenic smokes, using techniques which arose directly out of liturgical observance. … At all events the incense-burner remained the centre of changes and transformations associated with worship, sacrifice, ascending perfume of sweet savour, fire, combustion, disintegration, transformation, vision, communication with spiritual beings, and assurances of immortality”

This painting on wood is available at the online store.