The Sporeling Sprout, which spawns in Zangarmarsh near Sporeggar, possesses a moveset that deals a mix of humanoid, undead, and elemental damage, all depending on which abilities you decide to use. Its attacks are as follows:
Personally, I find it absolutely infuriating when my enemy has an ability like Charge. There are many attacks in pet battles that do bonus damage based on whether you attack first or second, so being aware of your speed in comparison to your enemy's speed is part of good play. If you expect to go first, but your opponent uses Charge, it can gut your damage. Having Charge in your toolkit can be quite a boon.
On the other hand, if you're intending to use your Sporeling Sprout as a dragonkiller, you may want to avoid Charge altogether. Many dragonkin have access to Tail Sweep, which does extra damage if the user attacks last. If you use Charge against enemies with that ability, you're enabling them to deal more damage to you. That's quite the gamble.
If you're willing to risk Tail Sweeps to utilize Charge, try to catch a Sporeling Sprout that's heavy on Health or Power, but low on Speed. If you can use Charge to attack first whenever you please, Speed stops being an important stat at all and allows you to pile on damage or HP. Note again that the humanoid passive ability works well here -- every turn you attack, you regenerate 4% of your maximum health. A healthy-heavy sporeling would gain greater benefit.
If you're planning on catching this little guy, don't forget to take your Terrible Turnip with you! Accidentally killing a rare-quality, health-heavy Sporeling Sprout would be heartbreaking.