flying
when you play jumbo imp, roll a six-sided die. jumbo imp comes into play with a number of +1/+1 counters on it equal to the die roll.
during your upkeep, roll a six-sided die and put on jumbo imp a number of +1/+1 counters equal to the die roll.
at the end of your turn, roll a six-sided die and remove from jumbo imp a number of +1/+1 counters equal to the die roll.