Your Dexterity score increases by 2. You also maintain some of your mental prowess from before the curse. Choose from Intelligence or Wisdom. Selected score increases by 1.

Cursed frogs rarely live longer than 10 years after the curse has been placed on them. Even if lifted, the curse has taken a toll on the body, and may reduce length of life significantly

While a cursed frog can be any alignment they tend to lean more towards chaotic, likely being the reason they got cursed in the first place

You can breathe air and water.

Accustomed to life in the swamp, you have superior vision in dark and dim conditions. You can see in dim light within 60 feet of you as if it were bright light, and in darkness as if it were dim light. You can’t discern color in darkness, only shades of gray.

Your base walking speed is 30 feet. You also have a swimspeed equal to your walking speed.

Your new frog-like body has granted you a few unnatural abilities. 

• You know the Poison spray cantrip.
• When you reach 3rd level you can cast the spell Jump once with this trait and regain the ability to do so when you finish a long rest.
• When you reach 5th level, you can cast the spell "Slime (Web reflavoured)" once with this trait and regain the ability to do so when you finish a long rest.

Your chosen mental stat is your spellcasting ability for these spells.

You also gain some benefits due to your new physique

• Standing Leap: You can perform a running leap without having a running start
• Cold Blooded: Being used to the cold waters of the swamp, you gain Damage Resistance to cold damage.

You can speak, read, and write Common, Bullywog and one other language you knew before being cursed. Bullywog is a nonsensical, gutteral and primal language. There isn't much of a written language, but some Bullywog shamans write in a script that often only makes sense to the writer.

A cursed frog stands between 4-5 feet tall. If you were taller before you were cursed you shrink to 5 feet, if you were shorter than 4 feet you do not grow. Your size is medium.