Kelp Cream (or Kelp Sauce) is a type of whipped cream that Patrick eats in the episode "SpongeHenge," and it only appears in that episode.
Kelp Cream looks like whipped cream but it is light green. Patrick seems to be very fond of it though it is unknown of how it tastes exactly.
It may possibly taste like regular whipped cream or it could be kelp flavored.
Role in the series
Patrick ate it when he watched TV. When the news came on the TV, Patrick threw the Kelp Cream/Kelp Sauce at the TV before SpongeBob came in, wanting to hide from the Jellyfish that wanted to listen to the music that SpongeBob's pores made.
It comes in a bottle that resembles most whipped cream bottles.