モリガン、[[バズヴ]]、マッハの3姉妹として登場することもある<ref name="Invasions">Macalister, R.A.S. (trans.), Lebor Gabála Érenn: Book of the Taking of Ireland Part 1-5, Irish Texts Society, 1941, Dublin</ref>。バズウ、マッハ、アナンダの三位一体で構成されることもあり、これらを総称してモリグナと呼ぶ。時折、ネマインやフィーアが様々な組み合わせで登場する。ただし、モリガンは単独で登場することもあり<ref name="CELT-Regamna"/>、彼女の名前は[[バズヴ]]と同じ意味で使われることもある<ref name="CMT166-CELT"/>。
モリガンは主に戦争と運命に関連しており、しばしば「戦争の女神」として解釈される。W.M.ヘネシーが1870年に書いた『古代アイルランドの軍女神(The Ancient Irish Goddess of War)』は、この解釈を定着させるのに大きな影響を及ぼした<ref>W. M. Hennessy, [http://www.sacred-texts.com/neu/celt/aigw/index.htm "The Ancient Irish Goddess of War"], ''Revue Celtique'' 1, 1870–72, pp. 32–37</ref>。彼女は、ホストたちが集まってくることに喜びを感じるという<ref>https://celt.ucc.ie//published/T106500D/text049.html, Part 49 of The Metrical Dindshenchas|website=celt.ucc.ie}}</ref>。
The Morrígan is mainly associated with war and fate, and is often interpreted as a "war goddess". [[W. M. Hennessy|W. M. Hennessy's]] ''The Ancient Irish Goddess of War'', written in 1870, was influential in establishing this interpretation. She is said to derive pleasure from mustered hosts.<ref>{{Cite web|url=https://celt.ucc.ie//published/T106500D/text049.html|title=Part 49 of The Metrical Dindshenchas|website=celt.ucc.ie}}</ref> Her role often involves premonitions of a particular warrior's violent death, suggesting a link with the [[banshee]] of later folklore. This connection is further noted by [[Patricia Lysaght]]: "In certain areas of Ireland this supernatural being is, in addition to the name banshee, also called the ''badhb''".<ref>{{cite book |first=Patricia |last=Lysaght |title=The Banshee: The Irish Death Messenger |year=1986 |isbn=1-57098-138-8 |page=15}}</ref> Her role was to not only be a symbol of imminent death, but to also influence the outcome of war. Most often, she did this by appearing as a crow flying overhead, and would either inspire fear or courage in the hearts of the warriors. In some cases, she is written to have appeared in visions to those who are destined to die in battle as washing their bloody armor. In this specific role, she is also given the role of foretelling imminent death with a particular emphasis on the individual.<ref>{{Cite book |title=Celtic Myths and Legends |last=Rolleston |first=T. W. |publisher=Barnes and Noble |year=1911 |isbn=978-0-7607-8335-1 |location=New York}}</ref> There are also a few rare accounts where she would join in the battle itself as a warrior and show her favouritism in a more direct manner.<ref>{{cite book |first=Arthur |last=Cotterell |title=The Encyclopedia of Mythology |year=2010 |pages=102, 152}}</ref>
The Morrígan is also associated with the land and animals, particularly livestock. [[Máire Herbert]] argues that "war ''per se'' is not a primary aspect of the role of the goddess." Herbert suggests that "her activities have a [[Tutelary deity|tutelary]] character. She oversees the land, its stock and its society. Her shape-shifting is an expression of her affinity with the whole living universe."<ref>{{cite book |first=Máire |last=Herbert |chapter=Transmutations of an Irish Goddess |editor1-first=Miranda |editor1-last=Green |editor2-first=Sandra |editor2-last=Billington |title=The Concept of the Goddess |publisher=Psychology Press |year=1996 |page=145}}</ref> Patricia Lysaght notes that the ''[[Cath Maige Tuired]]'' depicts the Morrígan as "a protectress of her people's interests" and associates her with both war and fertility.<ref name="lysaght"/> According to [[Proinsias Mac Cana]], the goddess in Ireland is "primarily concerned with the prosperity of the land: its fertility, its animal life, and (when it is conceived as a political unit) its security against external forces."<ref name="MacCana"/> Likewise, [[Maria Tymoczko]] writes, "The welfare and fertility of a people depend on their security against external aggression," and notes that "warlike action can thus have a protective aspect."<ref name="tymoczko"/> It is therefore suggested that the Morrígan is a manifestation of the [[Sovereignty goddess|earth- and sovereignty-goddess]],{{sfn|Ó hÓgáin|1991|pp=307–309}}<ref name="Koch, John T. 2006"/> chiefly representing the goddess' role as guardian of the territory and its people.<ref name="lysaght"/><ref name="tymoczko"/> She can be interpreted as providing political or military aid, or protection to the king—acting as a goddess of sovereignty, not necessarily of war.