Walrus blubber

This was the conversation at our dinner table the other night:
Jeffrey: "Mom, can we have a dog?"
Owen: "No, Jeffrey. Mom and Dad are allergic to dogs...remember?!?"
Jeffrey:"Oh ya. But Owen and I aren't allergic to dogs right?"
Mom: "Right."
Jeffrey: "Ya, we're just allergic to walrus blubber."
Mom: "Walrus blubber?"
Jeffrey: "Yup, that's what Grandpa told me, we're allergic to walrus blubber."
(hysterical laughing ensues...)
Jeffrey: "Mom, what is walrus blubber?"