Show him a fake article in a magazine that shows a high body for percentage is healthy and that being so skinny is "dangerous"

He might bite, but he'll bring up the risk of becoming grounded, aka lose the ability to take off and fly...

Double-dog dare him into drinking the contents of a chocolate shake machine without letting him stop once he starts. 🐸🎈💥

That might work once, but just once! XD

Once is enough. 🐸🎈🥓🥓🥓🥓💥

"Lifetime supply of" anything fattening or something you crave is always fun

Something he treats himself like once every 6 months, like a donut.

Exactly

Give him a opportunity of a lifetime, a job/promotion with benefits and great pay, though the long hours of sitting behind a desk and tasting dishes that come to him via mailroom department deliveries that are expected to be eaten and package remains to be collected by said department before he can clock out. I can see him expanding well past a cubicle in a few weeks

Mrrrrf, hot! Thank you! <3

If it's girth, not weight, various products that make him rounder and lighter will work. He can still fly, but he'll end up a balloon.

Indeed, but weight is more... forbidden for a stork! >:D

Well, it's not mutually exclusive. The New Goodyear Blimp weighs almost 20,000 lbs before inflation.

A stork, eh? Well... Increase his delivery packages to be heavier and more frequent, get him feeling the strain some... and as he starts to get accustomed to them slowly but steadily dose his meals with flavour enhancers and fattening agents...

... And as you increase the doses, slowly decrease the weight of the deliveries... Making his flights feel no less laboured... Going out and coming back with a bigger belly by the day, relieved each day he's back on the ground with all his deliveries done for the day...

... By the time he realises what's been happening the last few weeks/months, it'll be too late for him to stop... I mean, he would stop, but those meals are just so tasty and irresistible by now...

Sneaky, gradual and effective, I love it! :D

I'm sure he's bound to have had thousands of customers being so fit and eager to deliver for everyone, what if they were all to repay the favour at the same time? With snacks... sooo so many snacks for our sheepishly big beaked friend.

He knows how food delivery works, I bet he'd hate seeing all those mountains of calories go to waste. Perhaps an enthusiastic Roo neighbour is the only one around when he starts doubting if he should be eating so much, deep in his home, where noone can see what you two get up to...

He does hate to see food go to waste, so that could work! >:D

I'm sure with you standing over him it'd be quite a sight to see, and not just for his growing belly ;3

I always have thought about getting him to do an escape room, pretty normal thing right? Well turns out it’s a “food” themed one, and you have to eat your way out of certain rooms, or weigh a certain amount to get the door to open, and even more fun (albeit quite fattening) rooms!

Nice try, but I doubt he'd be that dedicated just to win a game!

Well it’s not just about winning the game, it’s about getting out! They are locked in there and he is gonna get restless and hungry I’m sure~

Oh I see.... no time limit and no help! Clever!

He's a delivery burb, but when unemployed, he tries anything to make ends meet, including keeping his new boss happy!

I can see a scenario where Pip is made to go deliver something random to a factory and get locked inside and find out its a donuts manufacturing plant

Classic set up!