There's a fair bit of complexity to this one, but it would be amazing if MOAs were able to jump on the backs of Warframes and sit or stand on their shoulders - just like when children ride on their parents shoulders - during idle times for both the Warframe and MOA. I'm not sure if this would break: Animation idea must not interact with anyone or anything else (ex. no handshakes) In the case of the Warframe it would still carry on with it's normal idle actions but the MOA would just hop onto it's back. I can see this however being an issue with a Warframe's idle animation causing it to break. Still, nevertheless I thought I would share this idea. TL:DR - The MOA would briefly hop on the Warframe's shoulders and then hop off shortly after.
The idea of this animation would be that the MOA replicates a bird pecking at a corpse. More specifically the MOA would lean over a dead enemy, whether it be Corpus, Grineer, Infested, etc. and peck at it's body.