CR 0–4 construct creatures from Monster Labs. These public stat blocks fit that band of the table; remix the CR or abilities if your party is ahead of the curve.
Warforged Harpoonist
CR 4 · Construct
Espada Vendaval
CR 4 · Construct
Jumping Ring Guardian
CR 4 · Construct
Stinky Cheese Golem
CR 4 · Construct
Dwarven Beer Golem
CR 4 · Construct
Magic Mirror
CR 4 · Construct
Rando-Tron
CR 4 · Construct
Mechanical Cyclops
CR 4 · Construct
Warforged Assassin
CR 4 · Construct
Scrapyard Guardian
CR 4 · Construct
Glass Reflection
CR 3 · Construct
Bee Robot
CR 3 · Construct
Gearizard
CR 3 · Construct
Fryblade
CR 3 · Construct
Genetic Mercenary
CR 3 · Construct
Arcane Trenchcoat
CR 3 · Construct
Faulty Automaton
CR 3 · Construct
Mechanical Mimic
CR 3 · Construct
Warforged Assault Unit
CR 3 · Construct
Rubber-Toothed Gearling
CR 3 · Construct
Clockwork Angel
CR 3 · Construct