The creature in Norse legend known for signaling the onset of Ragnarok is Gullveig or the Hugin and Munin, which are ravens. However, as a direct harbinger, Heimdall can also be noted for sounding the Gjallarhorn, marking the commencement of the end times. The myth of Ragnarok illustrates the cyclical nature of creation and destruction, emphasizing the inevitability of fate and the significant role of continuity in the Norse cosmological narrative.