Once a day the imp can use its action to polymorph into a beast form for 1h that resembles a rat (speed 20 ft.), a raven (20 ft., fly 60 ft.), or a spider (20 ft., climb 20 ft.), or back into its true form. Its statistics are the same in each form, except for the speed changes noted. Any equipment it is wearing or carrying isn't transformed. It reverts to its true form if it dies.

Darkvision 120 ft.Magical darkness doesn't impede the imp's darkvision.

 At lvl 5 The imp can use a action to magically turns itself invisible once a day which last for 10min or until you attacks or until your concentration ends (as if concentrating on a spell). Any equipment the imp wears or carries is invisible with it. Resets after a long rest. 

Your Dexterity score increases by 2, your strength score decreases by 1 and your Charisma score increases by 1.

No one really knows how long Imp's live, but hese imp's that have lost some connection to there devilish background seems to live around 500 years

These Imp's have no needs to go down the evil path and tends to hold them self neutral. Most creatures still perceive them as evil though.

Imp's are smaller than humans in build and size. Your size is small

Your base walking speed is 25 feet.

You have resistance to fire damage.

You know Infernal and common

There body has goten to big but there wings stayed the same. flying is abit harder for them now. they cast fly on themself once a day. Gaind at lvl 3 and resets after a short or long rest.