The Judgment of the Dead in the Presence of Osiris, ca. 1275 BCE; Wikimedia Commons
Medium: Papyrus
Dimensions: Height: 39.8 cm (15.6 in) 
; Width: 550 cm (18 ft)
Location: British Museum
"The scene reads from left to right. To the left, Anubis brings Hunefer into the judgment area. Anubis is also shown supervizing [sic] the judgment scales. Hunefer's heart, represented as a pot, is being weighed against a feather, the symbol of Maat, the established order of things, in this context meaning 'what is right'. The ancient Egyptians believed that the heart was the seat of the emotions, the intellect and the character, and thus represented the good or bad aspects of a person's life. If the heart did not balance with the feather, then the dead person was condemned to non-existence, and consumption by the ferocious 'devourer', the strange beast shown here which is part-crocodile, part-lion, and part-hippopotamus." (Khan Academy)
Ammit is generally translated as the “devourer” but sometimes also as “bone eater” or "eater of hearts" or “devourer of millions.” She was usually portrayed with the head of a crocodile, the body of a lion and the hindquarters of hippopotamus. "Ammit was not worshiped; instead, she embodied all that the Egyptians feared, threatening to bind them to eternal restlessness if they did not follow the principle of Ma'at." (Wikipedia)
A few sources for more information: