The phrase "little pea" refers to someone or something small and adorable, similar to a small vegetable called a pea. It's usually used affectionately to describe someone or something cute and sweet. Full definition
Once the oil is incorporated, causing the flour to form little pea sized clumps throughout, add the almond milk and apple cider vinegar. (faring-well.com)
I love how the twins are always together in the photos like two little peas in a pod! (emilyaclark.com)
It's one of Little Pea's favorite meals. (veggietot.com)