Teenagers Battle the Thing (1958)
Sounds like a spoof of 50's monster movies, but it's the real thing. Ultra-low budget black-and-white quickie, apparently never released in theaters, runs less than an hour. A teacher and some students go digging for artifacts somewhere out West. They find a Stone Age tool (sure looks like just a rock to me) so the males go climb a huge boulder while the two females wait below. The guys find a big rock, pry it up, and find the opening to a big cave. They go inside and find a "mummy" (dead guy covered with solidified mud or some such.) (The opening narration prepared us for the fact that this is an ancient "ape man" of some kind.) Somehow they haul it out of there and drag it off in a pickup truck to some building or other. It comes to life, menaces some folks, the teacher and the students and the local cop wait for it, it shows up, they throw gasoline on it and set it on fire. The end. Laughably awful monster suit, in the style of Larry Buchanan.
Curse of Bigfoot (1976)
Some guy in a cheap monster suit stalks a woman and her dog very slowly. Just as the attack is about to happen, we find out that we've been watching a movie-within-the-movie. Some students (high school or college), apparently taking a class in Monsters, listen to a teacher talk about Yeti/Bigfoot. This leads to a lot of stock footage of snowy mountains, forestry workers shoving big logs around, etc. We also get a fictional sequence of a couple of guys getting attacked by Bigfoot. (All we see is the big foot.) Back to the classroom. After some chatter (the whole class laughs hysterically when one student says that griffins ate everything of their victims except the shoes), the teacher introduces a guest speaker, who actually encountered Bigfoot. The guy comes in and explains that the incident was so horrifying that three of the folks involved spent the rest of their lives in mental institutions. We then go into flashback mode and find out . . . the rest of the movie is our old friend Teenagers Battle the Thing, but this time it's in color. It must have been filmed that way, then printed in black-and-white. I guess they printed it in color years later and added half an hour of introductory padding. I didn't bother watching this thing again, but flipping through it convinces me that they just slapped the old movie at the end of the new footage; we never do go back to the classroom. Both versions are awful, but Teenagers Battle the Thing has a certain 50's charm which is lost in the color version. It also has the not inconsiderable virtue of being only two-thirds as long as Curse of Bigfoot.