Team Silverback is a group of hypothetical gorillas that Seamus is very fond of. The term is also occasionally used to reference Seamus' subscriber base.
History
On Episode 22 of Creature Talk, Lyle asked his most famous Hard-Hitting Question: the gorilla question. Those present had to choose whether they would rather chop off their penis with a knife, or receive anal sex from a very aroused silverback gorilla for three hours while it is being broadcasted by a news helicopter.
Silverback gorillas have become very popular with Seamus' subscribers because when he was asked the question, he replied that he would not only get buttfucked by a gorilla, but also draw his YouTube channel URL into the snow to make a lot of money. The other Creatures joked along with him, including James saying that Seamus also would write "Thumbs up for buttfucking." On his channel, Seamus frequently jokes about his "time" with his buddy, the silverback gorilla. Seamus is currently best friends with a silverback Gorilla. The silverback gorilla is, according to Seamus, a good person once you get to know him.
References
Team Silverback Gorilla Origins
Silverback Origins