Die-hard fans have probably spent the last few weeks grumbling over the lack of loyal Panthro on the 'ThunderCats' roster, but the old favorite made a triumphant return in the final minutes of last week's episode.

There wasn't time to answer many questions in the last installment, but tonight's episode, 'Old Friends,' will fill in plenty of gaps, utilizing flashbacks to great effect to give us a brief history of Panthro's journey.

If you haven't had a chance to watch yet, tonight is a great starting point, since you'll get all the backstory in one handy bite.

Join us after the jump for some highlights from tonight's episode. Light spoilers ahead!

'ThunderCats' HOOOOOO!

Sorry, I just had to get that out of my system. It's been 20 years since the intrepid inhabitants of Thundera last roared across our screens (yes, the original series ended in 1989), and since then, 'ThunderCats' has lived on in the minds of nostalgic Gen X-ers and millennials through T-shirts and trips to YouTube, gone and mostly forgotten.

Our memories may be forgiving, but the well-intentioned series doesn't exactly hold up to repeat views (select episodes are available on KidsWB.com, if you're curious) and the campy costumes and earnest dialogue seemed long overdue for an update. Cartoon Network has taken up the task, turning to Studio 4°C, the animation house behind portions of the 'Batman: Gotham Knight' and 'Animatrix' movies to update the visuals. The tone is darker, the story more focused and relatable, and the dynamics between characters have shifted to reveal new conflicts that will drive the narrative. All in all, it's nothing to Snarf at.

Join us after the jump for our take on the new series, including five facts you should know before watching. Mild spoilers ahead.