Yo i have 2 ideas,and that is:
1.add and item called rock/boulder
Can be resized
Can smush Murray
Can spawn or summon
Can be grabbed and flinged
And if max amount is more than one...just do the thing you did with grenades(no explosions tho coz it's literally a rock/boulder)
2.HEAVY anvil
Smack and turn Murray into pancake
Only 1 cuz lag(maybe will idk)
Grabbable
Resize
HEAVY
BTW you can add both or 1 of them but idc,as long as you add them...I'm happy :)
(Idc if you add or not)