 While working on the animated television series Rocko 's Modern Life , Phineas and Ferb co @-@ founders Dan Povenmire and Jeff " Swampy " Marsh utilized several recurring elements in the episodes that they wrote . Among these were actions sequences and chase scenes . Povenmire and Marsh wanted to reuse these elements in their series and chose Perry to execute it . The pair gave him a consistent and continuous nemesis in the form of Doofenshmirtz as a means of allowing viewers to get to know him . 
 While working on the animated television series Rocko <a href='null_genetive' title='1'><mark>'s</mark></a>Modern Life , Phineas and Ferb <a href='uninflect' title='2'><mark>co</mark></a> @-@ <a href='uninflect' title='3'><mark>founders</mark></a> Dan Povenmire and Jeff " Swampy " Marsh utilized several recurring elements in the episodes that they wrote . Among these <a href='uninflect' title='4'><mark>were</mark></a> actions sequences and chase scenes . Povenmire and Marsh wanted to reuse these elements in their series and chose Perry to execute it . The pair gave him a consistent and continuous nemesis in the form of Doofenshmirtz as a means of allowing viewers to get to know him . 
While working on da animated television series Rocko  Modern Life , Phineas and Ferb coed @-@ founder Dan Povenmire and Jeff " Swampy " Marsh utilized several recurring elements in the episodes that they wrote . Among these was actions sequences and chase scenes . Povenmire and Marsh wanted to reuse these elements in their series and chose Perry to execute it . The pair gave em a consistent and continuous nemesis in tdaform of Doofenshmirtz as a means of allowing viewers to get to know hem.