He looks like Squidward, except the Winter Squidlock is light blue, has black pupils, and wears a blue and white shirt and a white skirt.
He first appears when the snowwoman introduces him along with a few others. He later appears around the Christmas Tree. He then falls backwards as the other elves open presents. He stops opening presents to say, "Happy..." [Insert Holiday Here] "...to you!"
"The 12 Days of Nickmas"
He first appears in the wide shot of the group. He then appears when SpongeBob the Elf sings, "12 bubbles blowing," and gets hit in the face with bubbles. He then appears when the two elves sing, "9 reindeer droppings," He then appears with some jellyfish singing, "six jamming jellies," He then appears when the four elves on roller skates roll by. He then appears in the wide shot when the group sings, "And a starfish on a pine tree."