Plot hole: In Ben's nightmare, Gwen says, "We will come and get you!" and then she nags at Ben for being the one with the alien powers, and she does not join him in climbing the tree. My guess is that this was due to a script error; it was likely supposed to be "he" (i.e. Ben) instead of "we".
Ben 10 (2005)
1 plot hole in Ghostfreaked Out
Starring: Tara Strong, Dee Bradley Baker, Paul Eiding, Meagan Smith
The Krakken - S1-E3
Continuity mistake: When The Krakken snatches the Cannery crate from the boat, you can see that the lower horizontal bar from the 'E' is suddenly missing, thus reading 'Cannfry'.
Grandpa Max Tennyson: Being a hero isn't about letting others know you did the right thing, it's about you knowing you did the right thing.
Ben Tennyson: What were you just doing, reading greeting cards back at the Mega Mart?
Grandpa Max Tennyson: Well... yes.
Trivia: 4-9 "Ben 10 vs The Negative 10 I": The holiday camp where Cooper is picked up by Max Tennyson looks quite like Camp Opinicon from season 2's "Camp Fear".