D&D 5E True Polymorph - Too powerful?

[Sorcerers Apprentice]

I'd rule that the 1000 head hydra needs to eat more than 10 times as much as a regular 9 headed hydra, meaning it will be busy eating and won't have time to fight any BBEGs.

 

[Maxperson]

I'd rule that the 1000 head hydra needs to eat more than 10 times as much as a regular 9 headed hydra, meaning it will be busy eating and won't have time to fight any BBEGs.

I'm a member of the club that thinks 1000 heads would weigh more than the body and the thing couldn't move or attack effectively.

 

[Voadam]

This sounds more like a Hydra issue than a Polymorph issue.

I think unlimited heads is silly whether you are on the player or DM side of things.

In general I would apply the older 3.5 Monster Manual rule on hydras which I think works well narratively and mechanically:

"A hydra can never have more than twice its original number of heads at any one time, and any extra heads it gains beyond its original number wither and die within a day."

 

[Nefermandias]

This sounds more like a Hydra issue than a Polymorph issue.

I think unlimited heads is silly whether you are on the player or DM side of things.

In general I would apply the older 3.5 Monster Manual rule on hydras which I think works well narratively and mechanically:

"A hydra can never have more than twice its original number of heads at any one time, and any extra heads it gains beyond its original number wither and die within a day."

This sounds more like a 5e design issue than anything else tbh.

 

[Iry]

I'm a member of the club that thinks 1000 heads would weigh more than the body and the thing couldn't move or attack effectively.

This. How the heck can it even move? 20 strength is probably not enough to haul around even 60 heads.