Big thanks to @Taweret for our special has-nothing-to-do-with-Easter Monsterdon Easter movie. Classic 1950s radioactive mutant animal(s) film.
We had smoking. We had coffee. We had a lot of exposition, little stock footage, and more than one monster. Monster(s) generated large amounts of spunk. Death count of nine. Minimal subplots. Reasonably dramatic final battle.
Aside from the titular monster, most memorable actor was the museum curator.