Blocked Antigravity Chocolate:
In the Poo Cabin, before or after it's been flooded, fall down the path. Climb up the first rope then jump to the second nearest available rope and climb it up. Get on the wooden platform, and when on it(or just swim all the way, if it's already flooded), adjust and look around with the camera a little until you spot an Antigravity chocolate.. Behind a gate! You can jump up there, but you cannot get the chocolate piece, as it's mysteriously blocked out of reach. By using moonjump codes or similar hacks, you can get behind the gate, and grab the chocolate, which restores one hit point like the others do. Despite what it looks like, there is no loading area behind the gate. It was planned to lead to an alcove, but the Conker guy left it in there just to mess with people. In fact, it is even in the L&R remake of the Single Player mode.
Out-of-Access Water Tile:
Conker:"Err… hey, level designers, i think you forgot to remove something here!…"
This is something rather odd that i found at the beach level in singleplayer mode. However it's completely out of reach, so the only way to get there is via cheating. It seems to be the spot seen.