/setblock ~0 ~1 ~0 mob_spawner 0 replace {SpawnCount:1,SpawnRange:50,maxNearbyEntities:5,Delay:20,MinSpawnDelay:6,MaxSpawnDelay:12,EntityId:Chicken,SpawnData:{Attributes:[{Name:generic.maxHealth,Base:50},{Name:generic.movementSpeed,Base:20.0}],ActiveEffects:[{Id:1,Amplifier:10,Duration:999999}],Invulnerable:1}}