Continuity mistake: Charlie Brown's Christmas tree is never the same. When we first see it, it has three branches. Later, when he's carrying it, it has four branches. Then, when he tries to decorate it and it flops over, it has six branches.
Continuity mistake: When the Pink Panther is sleeping on the bear-skin rug, the price tag reads "$350-00." When he rides in the rug, the two end zeros have disappeared, and in the shot after that, they are back again.