We’re up to the letter U – a little trickier than a letter like S or T! But when I think of U, I think of Under the Sea. So here are a few of my Disney World “Under the Sea” inspired pictures:
Ursula on the Under the Sea ride:
Meeting Ariel in her “Under the Sea” costume:
A real “under the sea” creature at Epcot’s The Seas:
Disney in Your Day 
Oh I love your choices for the theme. The seahorse is fantastic. I am always amazed by the beautiful fish and exhibits from “under the sea” at Epcot!