Crafty Cutpurse enters the battlefield, causing all tokens that would be created under an opponent's control this turn to be created under your control instead.
Activate Questing Phelddagrif's first ability by paying ({G} magic symbol) , causing Questing Phelddagrif to get +1/+1 until end of turn and creating a 1/1 Hippo creature token.
Activate Phyrexian Altar by sacrificing the Hippo token, adding ({G} magic symbol) .
Repeat from step 3.
Results
Infinite death triggers.
Infinite ETB.
Infinite LTB.
Infinitely large Questing Phelddagrif until end of turn.