"My baby!!!!!!!!" Jenner captioned a super-cute slideshow of snapshots showing her daughter's over-the top lavender look, along with a dozen purple heart emojis. "I cant handle this!!!!"
Stormi brought some real runway flair to the impromptu photoshoot, modeling her adorable costume, which included a long, silver-purple wig, and a shimmering dress with feathery purple fringe around the sleeves and the hem.
Stormi -- whom Jenner shares with her ex, Travis Scott -- looked adorably bewildered in the way that only a toddler can when decked out for Halloween.
Meanwhile, Jenner stunned in her own right giving off serious mermaid vibes at the Met Gala in May, where the theme was "camp" couture.
Check out the video below for a look at Jenner's striking, perfectly purple 2019 Met Gala style.