I remember watching this movie between 2006 and 2010. It was about a group of friends, the main character being a purple starfish. The main idea of the plot was that they were climbing up this mountain that was actually a volcano and it started to erupt. All but one of the friends made it to safety, so the friends who were at the base of the volcano had to save the friend from the lava.
Thank you for you suggestion, but I know that it’s definitely not spongebob (I love that show)