Next Time our Campaign ideas - resist physical attacks

 Reskin the lava child to make it look cool. BUt it is anti metal, so interesting. 
Dont forget heat metal options. 

https://5e.tools/bestiary/lava-child-wdmm.html

Resist all physical (sort of) list: https://www.reddit.com/r/dndnext/comments/pfqdm5/are_there_any_monster_resistant_to_all/

HagsBook says:

     So, I have checked:

MM:

Awakened Shrub (only flat piercing)
Awakened Tree (bludgeoning, piercing)
Flameskull (piercing)
Swarm of Bats/Beetles/Centipedes/Insects/Poisonous Snakes/Rats/Ravens/Spiders/Wasps
Treant

Volo:

Swarm of Cranium Rats/Rot Grubs
Thorny
Vegepygmy and Chief (piercing)
Wood Woad   

See demilich talk:. Resists a lot but not:

     Funny thing, Demiliches resist B/P/S only from magical weapons specifically, technically they can still take B/P/S damage from the following spells;

Arcane/Bigby's Hand

Black Tentacles
Blade Barrier
Catapult
Cloud of Daggers
Control Water (Whirlpool option)
Cordon of Arrows
Dust Devil
Earth Tremor
Earthquake
Ensnaring Strike
Erupting Earth
Hail of Thorns
Ice Knife
Insect Plague
Investiture of Wind
Maelstrom
Maximilian's Earthen Grasp
Meteor Swarm
Storm Sphere
Thorn Whip
Tidal Wave
Transmute Rock
Tsunami
Wall of Thorns
Whirlwind
Wind Wall

Wrath of Nature (Trees or Rock options)