Judging from its sphere design, I'm assuming that the Subterra Bakugan in the dog's mouth might be (coincidentally) a dog-like Bakugan. (MRRobinson (talk) 05:08, July 29, 2018 (UTC))
That's Lightning. Signed, H. Zeraora
Hyperus is right. The Bakugan Wiki outside of Wikia also confirms that the dog is named Lightning: https://bakugan.wiki/wiki/Lightning This also could be seen in the now deleted video by Negative Legend.
Moviejunkie2009 (talk) 13:06, December 15, 2018 (UTC)