1. In the season six episode "A Party for Tarzan," Blue Morpho takes a jade dragon from Dr. Z 

undefined
Adult Swim

Then, in the season seven premiere, we see Quizboy walk right by the jade dragon

undefined

Adult Swim




2. In season two's "Escape to the House of Mummies pt. 2," Dr. Venture mentions that his great-grandfather was a milliner

undefined

Adult Swim


The ghosts that The Venture family and the Order of The Triad encounter in the season seven opener were involved in the millinery fire that Dr. Venture's great-grandfather may have started

undefined

Adult Swim



3. Dr. Dugong is "killed" after an encounter with The Monarch in the season three episode "Tears of a Sea Cow"

undefined
Adult Swim



Later in season seven's "The Rorqual Affair" we learn that Dr. Dugong survived thanks to his starfish DNA (he's also Wide Wale's brother)

undefined
Adult Swim

 


4. Season seven's "Arrears in Science" comes full circle from PROBlem's first appearance, in the second episode of the whole series -- called "Careers in Science" 

undefined
Adult Swim



5. In season one's "Past Tense," Kano makes his first major appearance and doesn't speak during the episode

undefined
Adult Swim

It's not until later in season seven that we learn Kano's vow of silence came after "killing" Vendata following the apparent death of Dr. Venture

undefined
Adult Swim



6. Also in season one's "Past Tense," Dr. Orpheus offers a foreboding prediction for Action Man

undefined

undefined

Adult Swim

Dr. Orpheus' prediction of the Action Man's stroke came true, two years and 17 days from when he made the prediction

undefined
Adult Swim



7. Monarch's armor in season seven's "The High Cost of Loathing" is a slightly modified version of the armor from season three's "The Family That Slays Together, Stays Together pt. 2" 

undefined

undefined
Adult Swim

 

8. In a season one flashback, we see a young Brock marching around in his State University football uniform

undefined
Adult Swim


Later in present-day season seven, Brock is seen wearing his old State University jersey again

undefined
Adult Swim


9. In season seven, we see a mountain of jackets in the mountain of jackets in the Venture compound hangar

undefined
Adult Swim

These are leftover from the Shallow Gravy music video seen in season 5

undefined
Adult Swim


10. In season seven, the Peril Partnership plants a mole in the Guild of Calamitous Intent

undefined

Adult Swim

The Peril Partnership didn't come out of nowhere -- it was actually first mentioned in the season two episode "Fallen Arches" 

undefined
Adult Swim




11. In season five, the gang is surprised to find that St. Cloud has bought the X-2

undefined
Adult Swim

In season seven, we see that St. Cloud is still keeping the X-2 in pristine condition

undefined
Adult Swim




12. In season seven, look closely and you'll see Gary grabs a box of Apple Mummy cereal from the cabinet

undefined
Adult Swim



Back in season three, a young Rusty namedropped Apple Mummy as one of his favorite cereals

undefined

Adult Swim


13. In season seven, Dr Mrs. The Monarch becomes Lady Au Pair

undefined
Adult Swim

Au Pair is her individual supervillain identity, first seen in season two

undefined
Adult Swim



14. The Creep has stolen many things from heroes and villains throughout the series. The Monarch, butter-glider from "The Diving Bell & The Butter-Glider", Tank Top's breastplate, Galacticon's foot, Baron Underbheit's shoulder pad, and PoseiDonJuan's trident 

undefined
Adult Swim



15. In season seven, a A framed photo of Dr. Z and Sergeant Hatred can be seen in the background

undefined
Adult Swim


This is a callback to season three's "The Buddy System," where Sgt. Hatred geeks out and asks for a picture with Dr. Z

undefined

Adult Swim