Deep beneath Earth's surface, tribes of various humanoid characters live and do battle with adorable little slugs. Why slugs? Because those harmless little critters transform into gigantic, ferocious battle beasts with varying abilities when they reach the speed of 100 mph. Joining a long list of monster-collecting toons such as Pokemon and Kaijudo, Slugterra has a fairly stale premise but executes it with eye-popping visual style and frenetic pace, broadly hitting the mark of its intended pre-teen male audience.
Eli Shane is a normal teen boy living a typical suburban life on the surface, but he has a family secret: his dad is a mighty slug slinger in the unknown world below. Humans don't know about the existence of Slugterra, and Slugterrans don't know about our Earth, but somehow the Shanes are in the loop on both. When Eli's dad is struck down by the villainous Dr. Blakk, one of his trusty slugs travels to Eli's above-ground home to recruit him to the fight. Eli agrees and embarks on a grand adventure that finds him making new friends of both the humanoid and slug varieties, learning the basics of slug slinging and collecting, and aiding in the fight against Dr. Blakk.
By far the best aspect of the show is its great art style, utilizing a cel-shaded CG approach to deliver fluid, kinetic visuals unlike anything else on TV. See the cover art? It's not just marketing hype, it's representative of the actual animation, and that high standard is upheld throughout the five episodes included on the DVD. The CG action is a bit floaty in the early going, as if the creators were still figuring out their tech toolbox, but quickly settles into more realistic character and camera movements in later episodes. The use of CG allows for some truly dynamic shots that keep viewers engaged in the near-constant action, while the cel-shaded overcoat gives the characters an added touch of warmth.
As for those characters, the humanoids are underdeveloped, with their focus more on exploring the art of slug-slinging than exploring their interpersonal connections. Eli's gang of fighters includes a cute girl/potential love interest, a huge bruiser with a soft heart, and a cowardly little rapscallion, and that's about as much depth as we get out of any of them. The slugs are even less developed, and they don't speak, but they're more appealing than the humanoids due to their incredibly high cuteness factor and their underlying transformative powers.
The DVD includes a lengthy intro to the series hosted by its creator and its story editor, with information about its creation and evolution. There are also a few inconsequential "slugisodes" that are supposed to be footage from the camera of the cute girl filmmaker character, basically just a few more snippets of animation that weren't in the shows.