Groups of Reptiles, Amphibians, Fish and Invertebrates

Cobras: a quiver
Crocodiles: a bask
Frogs: an army
Toads: a knot
Turtles: a bale or nest
Salamanders: a maelstrom
Snakes, vipers: a nest

Fish in general: a draft, nest, run, school or shoal
Herring: an army
Sharks: a shiver
Trout: a hover

Bees: a grist, hive or swarm
Caterpillars: an army
Clams: a bed
Crabs: a consortium
Cockroaches: an intrusion
Flies: a business
Grasshoppers: a cloud
Jellyfish: a bloom, fluther or smack
Lobsters: a risk
Oysters: a bed
Snails: a hood
Squid: an audience