is it possible to modify master mode pets/items ?

[mddznyan]

So i am starting my own ressource pack and wanted to change a master mode item the name and tooltip but it is not working, i am actually not sure if its possible to modify these type of items.

 

[fireom21]

it is possible, melster's minecraft texture pack modifies the master mode skeletron pet

 

[mddznyan]

(its good that its possible, but i dont know what code i must type to get it work)
nvm than, thanks fireom. found the code and changed it ( worked now)
for example for a master mode pet: "KingSlimePetItem": "Summons the lost slime kings son\n'ngl but that slime is funky.'", ( is for the tooltip)