From Steve Spangler Science:

Steve brings a new twist to his classic Elephant's Toothpaste experiment with the addition of a little Halloween spirit... and some giant pumpkins.

More: http://www.stevespanglerscience.com/halloween-science-secrets.html

Steve Spangler is a celebrity teacher, science toy designer, speaker, author and an Emmy award-winning television personality. Spangler is probably best known for his Mentos and Diet Coke geyser experiment that went viral in 2005 and prompted more than 1,000 related YouTube videos.

The video: