Love and Monsters (2020) on Netflix

Plot summary

After an asteroid is destroyed above Earth and its chemical fallout mutates cold-blooded animals into giant monsters, teenager Joel Dawson loses touch with his girlfriend Aimee as Fairfield is evacuated. Seven years later he lives in an underground colony, where the other survivors fight monsters and pair off while he works as the cook, known for freezing when danger comes. When a giant ant breaks into the bunker, Joel decides to cross the surface and reunite with Aimee. The others hand him a map and a crossbow. In the suburbs a stray dog, Boy, saves him from a giant toad and follows him, warning him off poisonous berries. Two survivors, Clyde Dutton and Minnow, pull him from a nest of worm-like sand gobblers and teach him basic survival skills before he carries on west.