There's something special about interspecies animal friendships, perhaps because they demonstrate that if animals can put aside their differences, there's no reason we humans can't do the same.
We've gathered 10 outstanding videos that showcase unusual animal kingdom friendships between dogs and primates, hippos and tortoises, and even cats and birds.
Have a browse through the video gallery and let us know in the comments below which critter buddies tugged at your heartstrings.