Can typically be identified thanks to the attire's characteristics: a red fur trimdress with red and green ribbons and white pom poms, red boots tipped with holly, red, oversized detached sleeves with white tips, a white fur trim choker with a holly, and a double pointed santa hat with two pink flowers.
May be depicted holding her weapon: a snowmanplushie wearing a blue ribbon, green mittens, and a Santa hat with equivalent pink flowers.
Note that it's possible (especially for older artwork), to depict Mirabilis in a winter outfit without it being the one described above, in which case this tag should not be used.