Slugterra

Slugterra is a television show made by a Canadian animation studio (Nerd Corps Entertainment, which is the same animation studio that made Dragon Booster, League of Super Evil, and Max Steel).

Eli Shane is a 15-year old teenager who on his 15th birthday, like other members of his family, goes to the underground world of Slugterra. This world underneath the surface has different races besides humans such as trolls and molenoids, advanced technology, and even little creatures called Slugs. These Slugs are integral to the environment and society in Slugterra especially when it comes to Slugslinging, where Slugs are shot through Blasters at high velocity to transform for an attack. There is however the malevolent Dr. Thaddius Black who is corrupting slugs into Ghouls for his purpose of trying to rule all of Slugterra. The only thing in his way is Eli and his Shane Gang who travel throughout the land, making friends of Slugs, and writing wrongs wherever they are.

The cartoon premiered on September 3, 2012, and now had 48 episodes. The series also has 5 movies canon to the continuity.

Tropes used in Slugterra include:

Elemental Powers: Each slug is classified as an element; the primary elements are four classical elements and also "energy", and then there are also five secondary elements.
Fusion Dance: If you put two capsules together then you can make a fusion, combining the function of two slugs which can be combined in this way.
Market-Based Title: In Latinamerica, the series is marketed as Bajoterra.
Mon Machine: The blaster can fire the slug faster and then will activate the morph. Different kind of slugs have different functions (except Flopper, which has no function).
Monster Upgrade: If a slug is fast enough (200 mph) then it will be "megamorph", which is more powerful than the ordinary morph. This condition is temporary.