Hungry Jaws of Fenris, Bite attack while casting?

From the Northlands Worldbook sourcebook from Kobold Press

Casting Time:

1 action

Range/Area:

Self

Components:

V, S, M

Duration:

Concentration, up to 1 minute

Source:

Northlands Worldbook, pg. 179

As a Magic action, you channel the power of Fenris, the Great Wolf, transforming your mouth into a gaping maw. This doesn’t impede your movement or actions, but you can’t speak or cast spells with verbal components for the duration.

While the spell is active, you can use your jaws to make a bite attack. On a hit, the target takes Piercing damage equal to 4d10 plus your spellcasting ability modifier and, and it has the Grappled condition (escape DC equals your spell save DC).

If you bite a target already Grappled by you, you can choose to swallow it, and the Grappled condition ends. A swallowed creature is shunted into a pocket dimension. While there, it has the Blinded and Restrained conditions, has Total Cover against attacks and other effects outside the dimension, and takes 19 (3d12) Force damage at the start of each of your turns. You can’t swallow a creature if you have already swallowed a creature using this spell.

A swallowed creature can make a save at the end of each of its turns. On a success, you vomit the creature to the nearest unoccupied space of your choice. The same thing occurs if the spell’s duration elapses.

Using a Higher-Level Spell Slot. The damage dealt by the bite attack increases by 1d12 for each spell slot level above 6th.

it doesn't seem to outright say, so I'm uncertain how to interpret this aspect of the spell: when you cast this spell, do you also make the Bite attack (presumably as an action) or is it meant to be read that it's an action to create the spell, and requires an action on the next turn to perform the bite attack?

No, you don't bite as part of casting the spell, and the spell also doesn't specify what action is used so RAW you can't actually use it to bite.

Quote from Davyd >>

No, you don't bite as part of casting the spell, and the spell also doesn't specify what action is used so RAW you can't actually use it to bite.

This sort of issue — which I guess boils down to a failure to explicitly state assumptions? — seems depressingly common in the third-party content that gets published here.

Few problems with this spell as written, it lacks an action economy or usage frequency to Bite and the Ability saving throw a swallowed creature can make.

I would make those corrections to it:

While the spell is active, you can take the Attack action to use your jaws to make a bite attack. On a hit, the target takes Piercing damage equal to 4d10 plus your spellcasting ability modifier and, and it has the Grappled condition (escape DC equals your spell save DC).

A swallowed creature can make a Strength save at the end of each of its turns. On a success, you vomit the creature to the nearest unoccupied space of your choice. The same thing occurs if the spell’s duration elapses.

Quote from MobiTraveler >>

it doesn't seem to outright say, so I'm uncertain how to interpret this aspect of the spell: when you cast this spell, do you also make the Bite attack (presumably as an action) or is it meant to be read that it's an action to create the spell, and requires an action on the next turn to perform the bite attack?

This spell's attack is really badly written. First, this is no, you don't make a bite attack. The only time you do that is when it tells you do it. It never tells you to ever make a bite attack. Not having a bite when the spell is cast is not necessarily an issue.

The issues are:

• It says, "As a Magic action, you channel the power of Fenris, the Great Wolf, transforming your mouth into a gaping maw." "As a Magic action" has no value here unless this a 5.14 book since the casting time is already 1 action which equals a Magic action.
• It never tells you how to make a bite attack, as an action, magic action, or bonus action.
  • This means that it is just an available attack for the duration.
  • To attack with the bite, you must take the Attack action or another action that allows for unrestricted attacks (No requirements that it is an unarmed strike or a weapon attack).
  • You can use it to make an attack of opportunity without a feat.
  • It allows you to grapple a creature of any size. A halfling can grapple the Tarrasque.
  • "If you bite a target already Grappled by you, you can choose to swallow it..." does not rely on hitting with a bite but implies that you still get to resolve a bite attack. Normally, Swallow is a separate action, not a rider effect to an attack and definitely not hit or miss
• It never actually tells you how to resolve the bite attack. This would default to a strength modifier to attack and spellcasting modifier to damage but should probably be a melee spell attack. compare to Vampiric Touch.

As a level 6 spell, the ability to generate that much damage potentially multiple times per turn (I don't know what classes get access to the spell and how easy it is to pair it with extra attacks) including a free grapple and potentially a swallow. That's nuts.

Just a level 2 Fighter Dip will give you Action Surge if you need to attack the same turn you cast it. On the turn after, it could allow you to attack at least once, grapple on a hit, bite/swallow with no save.

Quote from Plaguescarred >>

Few problems with this spell as written, it lacks an action economy or usage frequency to Bite and the Ability saving throw a swallowed creature can make.

I would make those corrections to it:

While the spell is active, you can take the Attack action to use your jaws to make a bite attack. On a hit, the target takes Piercing damage equal to 4d10 plus your spellcasting ability modifier and, and it has the Grappled condition (escape DC equals your spell save DC).

A swallowed creature can make a Strength save at the end of each of its turns. On a success, you vomit the creature to the nearest unoccupied space of your choice. The same thing occurs if the spell’s duration elapses.

I didn't even notice the lack of a save attribute.

I would:

• Make it a Magic action to attack with a bite a melee spell attack.
• Restrict the grapple to creatures no more than one size larger than the caster.
• Require a Bonus Action to swallow a grappled creature and you do not resolve a bite attack against the creature. "If you bite a target already Grappled by you, you can choose to swallow it As a Bonus Action, you may choose to swallow a creature grappled by you and the Grappled condition ends on it."
• The Strength save you suggest sounds good.

Quote from SmiteMakesRight_3_5 >>

• Make it a Magic action to attack with a bite a melee spell attack.
• Restrict the grapple to creatures no more than one size larger than the caster.
• Require a Bonus Action to swallow a grappled creature and you do not resolve a bite attack against the creature. "If you bite a target already Grappled by you, you can choose to swallow it As a Bonus Action, you may choose to swallow a creature grappled by you and the Grappled condition ends on it."
• The Strength save you suggest sounds good.

 This actually make even more sense i agree.