Which of these characters came first

Killer Croc and Lizard

Crossbones and Bane

I read somewhere that they're rip offs of each other and I wanted to find out who's ripping off who?

Killer Croc [1983] The Lizard [1963]

Crossbones [1989] Bane [1993]

For future reference you can just search the character then click the link of the issue they first appeared in which will tell you the year it came out in.

I think there's more to "rip off" than similar character look. Killer Croc & Lizard "the men" couldn't be more different. Maybe one could be inspired by another, but they don't have to be flat out "ripping it off".

Since comics exist in their own world, they are inspired by each other even the early days when they were linked to pulps. For example Batman is inspired by The Spirit and Black Bat, whilst The Metal Men have direct influences from the Fantastic Four, hey they even spoofed their stories.

Wikipedia is a good resource for things like this.