Yes because big bird has a secret personality that turns him into lucifer. It can be accesed by prompting him with cookies. This is the reason that big bird and cookie monster never appear at the same time. During Sesame Street and the abc's the videogame there is a secret number counting level where you can prompt big bird to perpanatly become lucifer/big bird.
The cookie monster steals your cookies because he is obviously hungry, and his favorite food is cookies. and in case anyone is wondering he is not gay he is awesome
Because first of all, his NAME is COOKIE monster and he likes his cookies.
Cookie monster 
The cookie monster fears cookies. The cookie monster fears maddy because she is one evil cookie loving monster with 8 legs...
ANY KIND!!! COOOOOOOOKKKKIE !!! The Cookie Monster was well known for loving a diverse range of cookies.
i think they did not change cookie monster to veggie monster i think they just have him eat veggies and cookies
random children
Because first of all, his NAME is COOKIE monster and he likes his cookies.
Cookie monster 
The cookie monster fears cookies. The cookie monster fears maddy because she is one evil cookie loving monster with 8 legs...
me want cookies!
It was the Hamburglar...
No! He Is a COOKIE monster, vegstables aren't exactly like cookies.
ANY KIND!!! COOOOOOOOKKKKIE !!! The Cookie Monster was well known for loving a diverse range of cookies.
Cookie Monster likes cookies the most.
gemma crowson (a.k.a cookie monster)
Cookie Monster loves all cookies but his favorite is Chocolate Chip cookies :) Hope this helps!
i think they did not change cookie monster to veggie monster i think they just have him eat veggies and cookies