Full description for the Arthropod Patron here

Arthropod Choice

Choose which Arthropod you draw power from and emulate, be it the flying wasps, the sneaky scorpions, the entrapping spiders, or the tough crabs.

Crab

You have chosen the Crab, hardened creatures of the deep. You gain benefits as you level in this class.

Scorpion

You have chosen the Scorpion, agents of stealth and assassination. You gain benefits as you level in this class.

Spider

You have chosen the Spider, mobile creatures that deny mobility to others. You gain benefits as you level in this class.

Wasp

You have chosen the Wasp, flying insects with painful stingers. You gain benefits as you level in this class.

Expanded Spell List

Spell Level	Arthropod Spells	Crab Spells	Scorpion Spells	Spider Spells	Wasp Spells
1st	detect poison and disease	shield	inflict wounds	jump	feather fall
2nd	spider climb	aid	pass without trace	web	levitate
3rd	stinking cloud	water walk	nondetection	slow	haste
4th	giant insect	stoneskin	greater invisibility	freedom of movement	confusion
5th	insect plague	antilife shell	mislead	contagion	telekinesis

Arthropod Aspect

You gain features based on your Arthropod choice.

Crab

You have chosen the Crab, hardened creatures of the deep. You gain following benefits.

• Your unarmored AC is equal to 13 + your Constitution modifier.
• You gain a swimming speed equal to your walking speed, and you can breathe underwater.
• You gain an unarmed strike that deals 1d6 + your Charisma modifier bludgeoning damage.
• You gain proficiency in Athletics.

Scorpion

You have chosen the Scorpion, agents of stealth and assassination. You gain the following benefits.

• You can take the Hide action as a bonus action.
• When you are hidden from a creature and miss it with a ranged spell attack, making the attack doesn't reveal your position. In addition, Eldritch Blast no longer requires a verbal component.
• You gain an unarmed strike that deals 1d6 + your Charisma modifier poison damage.
• You gain proficiency in Stealth

Spider

You have chosen the Spider, mobile creatures that deny mobility to others. You gain the following benefits.

• You gain a climbing speed equal to your walking speed.
• You are immune to the effects of the Web spell and other web-like effects.
• You gain an unarmed strike that deals 1d6 + your Charisma modifier poison damage.
• You gain proficiency in Acrobatics

Wasp

You have chosen the Wasp, flying insects with painful stingers. You gain the following benefits:

• You gain a flying speed equal to your walking speed. If, at the end of your turn, you have not landed, you fall.
• You gain an unarmed strike that deals 1d6 + your Charisma modifier poison damage.
• You gain proficiency in Perception

Summon Arthropods

You gain the Speak with Animals spell, and can cast it at will, but can only use it to speak with the Arthropod of your choice.

In addition, you gain the Conjure Animals spell, and can cast it once at your pact magic spell slot level without expending a pact magic spell slot, and regain the ability to do so after a long rest. However, you can only conjure a Swarm of Insects based on the Arthropod of your choice. The stat block is indicated below, but the actual appearance of the swarms is based on your arthropod choice, not the stat block creature name.

• Wasp: Swarm of Insects (Wasps)
• Scorpion: Swarm of Insects (Centipedes)
• Spider: Swarm of Insects (Spiders)
• Crab: Swarm of Insects (Beetles)

Swarm of Arthropods

You can summon a swarm of your Arthropod to surround you, affecting creatures that dare approach you. As a bonus action, you can summon a swarm of your arthropod that extends from you as a 10 foot radius, and can deactivate the swarm as a bonus action. While the swarm is active, the area of the swarm is difficult terrain for creatures of your choice. Furthermore, you gain an extra action based on your arthropod. The swarm dissipates if you are Unconscious.

At level 18, the range of the swarm increases to 15 feet.

Crab

You summon a swarm of Crabs. As an Action, you can cause the crabs to attempt to grapple creatures of your choice within the swarm. The crabs' athletics bonus is equal to your Charisma modifier plus your proficiency bonus. If the crabs successfully grapple a creature, you can choose to move that creature to any other point within the swarm as part of this Action.

Scorpion

You summon a swarm of Scorpions. As an Action, you can cause the scorpions to swarm creatures of your choice within the swarm, stinging them and causing them to be Poisoned while they remain in the swarm. The effect ends when they leave the swarm. Creatures immune to the Poisoned condition are not affected.

Spider

You summon a swarm of Spiders. As an Action, you can cause the spiders to lay down webbing all along the area of the swarm. Creatures that begin their turn in the swarm or enter the swarm on their turn must make a Dexterity saving throw equal to 8 + your Charisma modifier + your proficiency bonus or become retrained. A creature restrained in this way can use its action to make a Strength saving throw against the save DC. If it succeeds, it is no longer restrained. The webbing only exists within the swarm, moves with the swarm, and does not leave a trail of webbing when the swarm moves.

Wasp

You summon a swarm of Wasps. As an Action, you can cause the wasps to swarm about creatures of your choice within the swarm, giving them disadvantage on attack rolls made while within the swarm. The effect ends when they leave the swarm.

Warlock: Become Arthropod

You have become so in tune with your Arthropod that you can become a swarm of your arthropod. As an Action, you transform into a swarm of your Arthropod. You gain benefits based on your swarm.

Crab

While transformed into a swarm of crabs, everything you wear and carry is transformed with you. The transformation ends when you drop to 0 hit points, or if you end it as a bonus action. You gain the following benefits:

• Your only movement speed is a walking speed of 20 feet and a swimming speed of 20 feet.
• You can enter and occupy the space of another creature, and vice versa.
• You have resistance to nonmagical damage, and advantage on Strength, Dexterity, and Constitution saving throws.
• You can pass through small holes, narrow openings, and even mere cracks.
• You can't talk or manipulate objects, and any objects you were carrying or holding can't be dropped, used, or otherwise interacted with. You likewise can't attack or cast spells.
• The damage dealt by your Arthropod Swarm becomes double your Charisma modifier.
• Creatures within your Arthropod Swarm have disadvantage to resist being grappled by your swarm.

Scorpion

While transformed into a swarm of scorpions, everything you wear and carry is transformed with you. The transformation ends when you drop to 0 hit points, or if you end it as a bonus action. You gain the following benefits:

• Your only movement speed is a walking speed of 20 feet.
• You have advantage on Dexterity (Stealth) checks.
• You can enter and occupy the space of another creature, and vice versa.
• You have resistance to nonmagical damage, and advantage on Strength, Dexterity, and Constitution saving throws.
• You can pass through small holes, narrow openings, and even mere cracks, though you treat liquids as though they were solid surfaces.
• You can't talk or manipulate objects, and any objects you were carrying or holding can't be dropped, used, or otherwise interacted with. You likewise can't attack or cast spells.
• The damage dealt by your Arthropod Swarm becomes double your Charisma modifier.

Spider

While transformed into a swarm of spiders, everything you wear and carry is transformed with you. The transformation ends when you drop to 0 hit points, or if you end it as a bonus action. You gain the following benefits:

• Your only movement speed is a walking speed of 20 feet and a climbing speed of 20 feet.
• You can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.
• You can enter and occupy the space of another creature, and vice versa.
• You have resistance to nonmagical damage, and advantage on Strength, Dexterity, and Constitution saving throws.
• You can pass through small holes, narrow openings, and even mere cracks, though you treat liquids as though they were solid surfaces.
• You can't talk or manipulate objects, and any objects you were carrying or holding can't be dropped, used, or otherwise interacted with. You likewise can't attack or cast spells.
• The damage dealt by your Arthropod Swarm becomes double your Charisma modifier.

Wasp

While transformed into a swarm of wasps, everything you wear and carry is transformed with you. The transformation ends when you drop to 0 hit points, or if you end it as a bonus action. You gain the following benefits:

• Your only movement speed is a flying speed of 30 feet.
• You can enter and occupy the space of another creature, and vice versa.
• You have resistance to nonmagical damage, and advantage on Strength, Dexterity, and Constitution saving throws.
• You can pass through small holes, narrow openings, and even mere cracks, though you treat liquids as though they were solid surfaces.
• You can't talk or manipulate objects, and any objects you were carrying or holding can't be dropped, used, or otherwise interacted with. You likewise can't attack or cast spells.
• The damage dealt by your Arthropod Swarm becomes double your Charisma modifier.