Logo copyright somewhat ambiguous, but I believe it's a modified version of O'Reilly's camel, which O'Reilly freely licenses for non-commerical usage. 

Special thanks to O'Reilly: https://www.oreilly.com/library/view/programming-perl-3rd/0596000278/ 

The state of Perl logos is a complicated topic. Python, Go, Ruby, Rust and PHP all have logos with permissive licenses to encourage the usage and brand-recognition of their respective languages.
Although The Perl Foundation (TPF) maintains an onion logo, they specifically use it as a TPF logo and do not allow it to be used for general Perl related projects.

I grabbed the shadow camel from the 2nd link below and recolored it to work well against a dark background.
This is essentially the same logo that vscode uses to indicate Perl file types, so the association will be strong among vscode users. 
Seems to work well against both the default dark background of the extension viewer, and the default white background of the extension marketplace webpage. 
To fill out the full 128x128, the camel got a bit wider, but the higher resolution skinny camel is included for completeness.

https://neilb.org/2020/12/04/perl-and-camels.html
https://dev.to/thibaultduponchelle/the-perl-complex-topic-of-logos-3161