I think learning the cognates of German words would really help learning German as I know through reading, 'deer' is a cognate of 'Tier', which I wouldn't have guessed otherwise
Yes, there is a list (probably not complete) at the Wiktionary Appendix:
Your example is listed at section
I think learning the cognates of German words would really help learning German
I am not a 100% sure if knowing more about the cognates really helps in learning the language, because it can lead to misunderstandings, and usage of notorious "false friends" in each other language.
I am trying to give you an example (and you can probably find many more from the list mentioned above):
Kraft (germ. for force, power) is a cognate with craft (in germ. Handwerk, Handwerkskunst ), which have completely different meanings in both languages.
I'd say knowing cognates starts to get interesting if you already know both languages at a mature and stable state. But for learning one of the distantly related languages not so much.
Wolfgang Pfeifer's excellent German etymological dictionary is incorporated in this site:
If there are English cognates they will be mentioned.