Which episode was this?
 

Been so long since I seen the show, uh there was this episode i watched where Casey Jones worked in an office and we saw Shredder as a baby using his claws and destroy all the toys.

I don't remember much of it.

Can anyone remember this episode?

whoa i dont remember that at all but i havent seen the last few seasons as much maybe the most ive seen an ep was twice the last few seasons

Corporate Raiders from Dimension X is the one you're referring too, I think.

Casey Jones went undercover for Octopus, Inc. in the episode Corporate Raiders from Dimension X.
The Shredder was only a baby once, in the episode Leatherhead: Terror of the Swamp...when he accidentally fell into the fountain of youth.
I think you are mixing your episodes... :D