I think this has been suggested before and even commented on from Red, but I can’t verify that. I feel like it would be just as Simple™ as coding a minion staff to spawn the existing animated sprite with the same player-following minion AI when placed in the pet slot but disabling its attack protocol.
Main issue I see is that, iirc, pets can also be summoned from the hot bar, so that could cause an item behavior conflict. There’s also stacking minions. Which size should the desert tiger use, or how does the player get to choose between the three levels? How long should the stardust dragon be, or how would the player set its length?