See also: Web (Phase Spider)
Web is a 
Bonus Action and 
Action. Spiders use this ability to shoot out webbing that can entangle creatures.
Description
Expel a thick, flammable webbing that slows creatures within and possibly
Enwebs them. 
Available only in combat.
Properties
- Cost:
-
Bonus action - Details:
-
Range: 18 m / 60 ft -
AoE: 3 m / 15 ft (Radius) - Creates Area: Web (surface)
-
DEX Save (Spell save DC)
Area: Web (surface)
Web 
Duration: 10 turns
AoE: 3 m / ft (Radius)
Difficult terrain - movement speed is halved. Can Enweb creatures. Prevents Falling damage. Flammable.
Type: Surface
Condition: Enwebbed
Enwebbed- Cannot move.
Attack rolls against the creature have 
Advantage, while the creature's Attack Rolls and Dexterity Saving throws are rolled with 
Disadvantage.
Condition: Difficult Terrain
Difficult Terrain- Movement Speed halved
How to learn
Used by creatures: Wild Shape: Spider, Wolf Spider Companion, Smaller Giant Spider, and Larger Giant Spider