These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Canon Sue: Yes, he's a Shane. But Eli is inexplicably better than everyone in the tournament, despite only being in Slugterra for a couple of days. He has a great bond with slugs he just met, and he can form complex strategies on a whim even though he was never hinted at having any strategic skill.
The above is only the first two episodes. Come episode 3, Dr. Blakk mops the floor with him. Eli and his friends barely managed to escape when Burpy did that firewall thing.
He displays racing skills that rival pros, despite almost never racing and isn't used to the terrain used in the race. This is lampshaded when he points out that he's only been riding for a short time.
Ethnic Scrappy: Pronto is seriously pushing this one. For that matter, we've seen two Molenoid villains before the reveal of their actual civilisation.