I saw an old movie (maybe tv show?) on tv when I was a little kid, probably would have been around 1990, but the movie was much older, perhaps from the 70’s. It was about a little girl who rescued a swamp creature from two guys trying to capture it. I think the girl wore yellow. The characters were all animated but they were put over shots of real-life backgrounds. I also remember several shots of just the woods/forest without any animation over it. The movie must have been fairly old because the animation was poor and the audio and video quality not very good either. It was a colour movie and in English. I have tried googling all kinds of descriptions to find it but with no luck. Any ideas?