1: [Young]
The Yelmut has fondness for a great many things. Topmost is its yodeling prowess, though its decorative headgear is a close second. Please don't call it a hat; it's a very touchy subject.
2: [Adult]
Having never taken it off, the adult Yelmut has grown into its ha-... I mean, decorative headgear, now weather-beaten and embellished with exotic designs. Its massive mouth carries its song far and wide... and with such intensity, its decorative headgear is in danger of being displaced!
3: [Prismatic]
This Yelmut returned from the Prism Gate forever changed! Having accepted the fact that its headgear will forever be mistaken for a hat, the now shaggy and grub-like Monster took advantage of the molecule-bending properties of the alien dimension and converted it into a stylish eggshell covering - extraordinary!