These five Belly Draggers from the episode, The Amazing Threehorn Girl, are a pack of Rutiodon. The subordinates appear as the secondary antagonists of the episode, while the leader is the main antagonist.
The leader and one of his brown subordinates first appear during the beginning of the episode. They are seen chasing the Gang of Seven, ending up cornering Cera while the other six escape. However, before they can attack her, several rocks fall towards the Rutiodon, causing them to quickly flee to avoid being crushed. Cera, who had her eyes closed the whole time, believes that she chased the Belly Draggers away and tells the whole Valley, leading to them venerating her as a hero. However, the gang find the leader along with two of his subordinates near the Great Valley, and leaving, presumably to gather a couple more of the crocodiles to attack later. Soon they enter the Valley.
They attack Cera during the climax of the episode, cornering her at the edge of a cliff. They prepare to attack her, but her father comes to protect her, ramming one of the brown Belly Draggers into the air, knocking it unconscious. They both yell, scaring three of the four remaining Belly Draggers, but the dull green Rutiodon leader is not intimidated and charges at Topps.
Topps stomps on it, and grabs its tail with his mouth and flings it into the air. The other three Rutiodon are scared and try to escape. Two of them get away, but the thrown Belly Dragger lands on top of a third brown-colored retreating one, knocking them both down. The rest of the Great Valley population later chase the two remaining Rutiodon out of the Great Valley.
- They are the only Belly Draggers from the TV series, the only Belly Draggers that hunt in packs instead of alone, and the only Belly Draggers that have ever gotten inside the Great Valley.
- In a couple of shots, the two brown Belly Draggers that help surround Topps and Cera have red eyes, akin to Tyrannosaurus from the first six The Land Before Time films.
- It is unknown as to what happened to one of the Belly Draggers that had been knocked out; it may have been chased away by the Great Valley herd after waking up, or it could have ran away afterwards, knowing it stood no chance against the herds.
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