How long is your (language) snake?
Here's a loop of 4 languages:

C -> Bash -> Batch -> Python -> C

C

main(){char *c="echo %cecho print %cmain(){char *c=%c%c%s%c%c;printf(c,34,39,92,34,c,92,34,39,34);}%c%c";printf(c,34,39,92,34,c,92,34,39,34);}


Bash

echo "echo print 'main(){char *c=\"echo %cecho print %cmain(){char *c=%c%c%s%c%c;printf(c,34,39,92,34,c,92,34,39,34);}%c%c\";printf(c,34,39,92,34,c,92,34,39,34);}'"


Batch

echo print 'main(){char *c="echo %cecho print %cmain(){char *c=%c%c%s%c%c;printf(c,34,39,92,34,c,92,34,39,34);}%c%c";printf(c,34,39,92,34,c,92,34,39,34);}'


Python

print 'main(){char *c="echo %cecho print %cmain(){char *c=%c%c%s%c%c;printf(c,34,39,92,34,c,92,34,39,34);}%c%c";printf(c,34,39,92,34,c,92,34,39,34);}'