Continuity mistake: As Gilligan marches over the cliff, he's wearing Skipper's hat. As he's hanging on the branch, his regular white hat is on his head.
How Green Was My Grass - S4-E24
Continuity mistake: Before this episode (and after as well) Darrin and Samantha give their address as 1164 Morning Glory Circle, however in this episode, when Darrin slams the door, the '9' in 192 on their address spins around to make 162, hence the angry neighbor at 162 saying that his grass was installed at the Stevens' by mistake.
Continuity mistake: When Scott is in the cockpit of the Mole, he has two blue tubes in the holsters of his belt. But when he is cutting through the fire doors, the tubes have changed to one blue and one yellow.
Continuity mistake: After Herman breaks through the doors in the opening sequence, the underlying wood over the right side of the hole is plain plywood. When it's Lily's turn to come out, the wood has been stained to match the rest of the door, and Herman's outline is more distinct.
The Addams Family Goes to School - S1-E1
Continuity mistake: After Mr. Hilliard goes through gate and nears the house, it's really at the real house. A second later, he's approaching the now-familiar front porch on the studio set. This is easy to tell because the layout of the two porches are radically different.
Emergency Marineville - S1-E11
Continuity mistake: When the second group of Spearhead jets take off from Marineville there are only two jets, but in the next shot you can see three jets, and in the next shot there are two again.
Continuity mistake: While Bud is napping/fishing in the skiff, Flipper grabs hold of the anchor line and tows the skiff. However, in Flipper's closeup, the anchor is missing from the line. Then it reappears when Bud pulls up the line and sets the anchor down in the skiff.