The Trees are a talking, forest-full of trees, who kidnap Carl once he dumps a giant vat full of waste into the woods (or their home/habitat). Once they see him dumping the liquids, they grab him and hold him hostage until Master Shake reports for his court summon. They also sent warning letters to Shake, instead of paper, however, they used Carl's skin, and sketched writing into it.
Eventually after receiving his second notice, and rejecting it once again, the trees stormed over to the Aqua Teens's house, kidnapped Shake, and forced him into court. Frylock was his lawyer, even though he was aware that he was guilty. Once Frylock tears out a page from a book of Tree Laws that reveals proof to the court that supports Master Shake's "innocence", the trees get shocked and the Judge orders the trees to seize him since paper is made from trees.
Frylock then fires his laser eyes directly at the trees, and they burst into flames. The Aqua Teens (along with Carl) manage to escape. The Judge is voiced by Dave Willis, while the Stenographer is voiced by Matt Maiellaro and the others are voiced by Jay Edwards, Jim Fortier, Ned Hastings, Nick Ingkatanuwat and Vishal Roney, while their Court-Appointed Shrub Lawyer assigned to the Aqua Teens.