 Perry and Doofenshmirtz at first seem to loathe each other in the beginning of the series , and have been arch @-@ nemeses since the day they met . However , they are often cordial and friendly towards one another and it is said by Doofenshmirtz that Perry is his best friend , and Perry will often act to save Doofenshmirtz 's life when his plot inevitably blows up in his face . Habitually , their daily brawls involve Doofenshmirtz devising a scheme , which Perry goes to stop after being briefed by Major Monogram . He is trapped by Doofenshmirtz while trying to do so and is told of the doctor 's scheme , usually pertaining to some backstory or pet peeve . He then escapes and the two fight , Perry coming out victorious . The two rely on this daily structure , Doofenshmirtz even specifically mentioning it in " Journey to the Center of Candace " and in episodes such as " It 's About Time ! " in which Doofenshmirtz temporarily replaces Perry with secret agent Peter The Panda and they become depressed about not having each other to fight . Perry realizes he misses Doof too . When Perry does not arrive on the scene of Doofenshmirtz 's evil plan , the doctor hesitates to execute his plans and fears for where Perry has gone , though he notes that he " hopes something terrible has happened to him . " . Sometimes , they decided not to fight and have fun , as shown in " Happy New Year ! " and " Candace Disconnected " . On other occasions , depending on whatever situation Doofenshmirtz is facing , Perry would often help Doofenshmirtz with his non @-@ evil plans , such as helping him overcome evil scientist 's block , helping him put on a birthday party for his 16 @-@ year @-@ old daughter Vanessa , impressing a square dancing girl with programmable square dancing boots that Doofenshmritz created , working together to stop a raging platypus hunter from hunting them down , or helping him convince his rich ex @-@ wife to help pay off his mortgage debt . Also , Perry tends to use Doofenshmirtz 's inventions to erase evidence of whatever contraptions Phineas and Ferb had made , leaving Candace unable to bust them . Examples include when Perry asked to borrow Doofenshmirtz 's robot Norm to pick up footage from the city surveillance cameras in order to preserve his job as an agent , as well as using Doofenshmirtz 's Pick @-@ Him @-@ Up @-@ inator to rescue a lost Candace and bring her home . 
 Perry and Doofenshmirtz at first seem to loathe each other in the beginning of the series , and have been arch @-@ nemeses since the day they met . However , they <a href='drop_aux' title='1'><mark>are</mark></a>often cordial and friendly towards one another and it is said by Doofenshmirtz that Perry is his best friend , and Perry will often act to save Doofenshmirtz <a href='null_genetive' title='2'><mark>'s</mark></a>life when his plot inevitably <a href='uninflect' title='3'><mark>blows</mark></a> up in his face . Habitually , their daily brawls involve Doofenshmirtz devising a scheme , which Perry <a href='uninflect' title='4'><mark>goes</mark></a> to stop after being briefed by Major Monogram . He is trapped by Doofenshmirtz while trying to do so and is told of the doctor <a href='null_genetive' title='5'><mark>'s</mark></a>scheme , usually pertaining to some backstory or pet peeve . He then <a href='uninflect' title='6'><mark>escapes</mark></a> and the two fight , Perry coming out victorious . The two rely on this daily structure , Doofenshmirtz even specifically mentioning it in " Journey to the Center of Candace " and in episodes such as " It 's About Time ! " in which Doofenshmirtz temporarily <a href='uninflect' title='7'><mark>replaces</mark></a> Perry with secret agent Peter The Panda and they become depressed about not having each other to fight . Perry <a href='uninflect' title='8'><mark>realizes</mark></a> he <a href='uninflect' title='9'><mark>misses</mark></a> Doof too . When Perry <a href='uninflect' title='10'><mark>does</mark></a> not arrive on <a href='None' title='11'><mark>the</mark></a><a href='negative_concord' title='12'><mark>scene</mark></a> of Doofenshmirtz <a href='null_genetive' title='13'><mark>'s</mark></a>evil plan , the doctor <a href='uninflect' title='14'><mark>hesitates</mark></a> to execute his plans and fears for where Perry <a href='been_done' title='15'><mark>has</mark></a> gone , though he <a href='uninflect' title='16'><mark>notes</mark></a> that he " <a href='uninflect' title='17'><mark>hopes</mark></a> something terrible <a href='been_done' title='18'><mark>has</mark></a> happened to him . " . Sometimes , they decided not to fight and <a href='got' title='19'><mark>have</mark></a> fun , as shown in " Happy New Year ! " and " Candace Disconnected " . On other occasions , depending on whatever situation Doofenshmirtz is facing , Perry would often help Doofenshmirtz with his non @-@ evil plans , such as helping him overcome evil scientist <a href='null_genetive' title='20'><mark>'s</mark></a>block , helping him put on a birthday party for his 16 @-@ year @-@ old daughter Vanessa , impressing a square dancing girl with programmable square dancing boots <a href='null_relcl' title='21'><mark>that</mark></a>Doofenshmritz created , working together to stop a raging platypus hunter from hunting them down , or helping him convince his rich ex @-@ wife to help pay off his mortgage debt . Also , Perry <a href='uninflect' title='22'><mark>tends</mark></a> to use Doofenshmirtz <a href='null_genetive' title='23'><mark>'s</mark></a>inventions to erase evidence of whatever contraptions Phineas and Ferb <a href='been_done' title='24'><mark>had</mark></a> made , leaving Candace unable to bust them . Examples include when Perry asked to borrow Doofenshmirtz <a href='null_genetive' title='25'><mark>'s</mark></a>robot Norm to pick up footage from the city surveillance cameras in order to preserve his job as an agent , as well as using Doofenshmirtz <a href='null_genetive' title='26'><mark>'s</mark></a>Pick @-@ Him @-@ Up @-@ inator to rescue a lost Candace and bring her home . 
Perry and Doofenshmirtz at first seem to loathe each other in da beginning of tdaseries , and have been arch @-@ nemeses since thdaay they met . However , they often cordial and friendly towards one anotha and it is said by Doofenshmirtz that Perry is his best homie , and Perry gon often act to save Doofenshmirtz  life when his plot inevitably blow up in his face . Habitually , their daily brawls involve Doofenshmirtz devising a scheme , which Perry go to stop after being briefed by Major Monogram . He is trapped by Doofenshmirtz while tryna do so and is tld of the doctor  scheme , usually pertaining to sum backstory or pet peeve . He then escape and the two fight , Perry coming out victorious . Thedao rely on this daily structure , Doofenshmirtz even specifically mentioning it in " Journey to the dater of Candace " and in episodes such as " It 's About Time ! " in which Doofenshmirtz temporarily replace Perry with secret agent Peter The Panda and they become depressed about not havin each other to fight . Perry kno he miss Doof too . When Perry do not arrive on no scene of Doofenshmirtz  evil plan , the ddaor hesitate to execute his plans and fears fir where Perry done gone , though he note that he " hope somthing terrible done happened to em . " . Sometimes , they decided not to fight and got fun , as shown in " Happy New Year ! " and " Candace Disconnected " . On other occasions , depending on whatever shyt Doofenshmirtz is facing , Perry would often help Doofenshmirtz with his non @-@ evil plans , such as helping him overcome evil scientist  block , helping him put on a birthday party for his 16 @-@ year @-@ old daughter Vanessa , impressing a square dancing gurl with programmable square dancing boots Doofenshmritz created , working together to stop a raging platypus hunter from hunting em dwn , or helpin hemconvince his rich ex @-@ wife to help pay offf his mortgage debt . Also , Perry tend to use Doofenshmirtz  inventions to erase evidence of whatever contraptions Phineas and Ferb done made , leavin Candace unable to bust them . Examples include when Perry asked to borrow Doofenshmirtz  robot Norm to pick up footage from the cidasurveillance cameras in order to preserve his job as an agent , as well as using Doofenshmirtz  Pick @-@ Him @-@ Up @-@ inator to rescue a lost Candace and bring her home .