Udyr needs some changes made, Here are some suggestions

Since patch 6.7 Udyr has been under performing since the R change. At that time Runic Echoes, Swift Boots and ZZrot Portal was his core items into tank stats and All of his core items got nerfed and he got nerfed on other patches before the 6.7 patch, but this patch they wanted him dead. I know that he doesn't need buffs but at least some identity in the game. Since he doesn't have an ultimate ability i expect him to excel at something but he doesn't have the best gank potential right now because most champs that are immobile have good amount of CC and he is very vulnerable against CC and he is easy to kite too, He isn't the best at clearing either compared to other junglers because maxing his Phoenix Stance is just not as effective as Tiger Stance. He isn't the best skirmisher ATM and doesn't have the best clear potential. I think Riot should make him like Shyvana or some what like Trundle. I know these champs are different but Shyvana has really good clears and because of that she lost some of her dueling power and she has no CC on her kit. Trundle on the other hand has decent clears but excels at dueling and peeling, Trundle is a good all around champion for what he provides to the team. Udyr doesn't fill this niche these champs have. I don't have a lot of examples but some changes that could be considered would be:

1. Passive reset timer doesn't fall when auto attacking Reason: Some of his clearing weaknesses come from him wasting too much mana on the first clear. Most often when going Gromp into blue he rans out of mana very quickly then when going for wolves I ran out of mana. The main reason he runs out of mana early is because his passive timer resets only when you activate a stance in the next 5 seconds.
2. Spend less mana on stances Reason: Same as the first reason, he has mana issues without blue.
3. Bigger mana pool/ regen Reason: This would be a big buff but i feel that it could be possible to increase his mana pool and/or regen for more sustain.
4. Turtle Stance scale with health rather than AP Reason: He should be rewarded for building health, his base numbers should be really low for this to happen ( Imagine Skarners' W)
5. Changing stances doesn't buffer Reason : For me its very annoying to use my Phoenix stance in the middle of a fight because he just stands there for a while before auto attacking. Considering he is an AS champion it is very akward.
6. Tiger stance DoT applies life steal Reason: If some changes are done to his Phoenix Stance i think helping his Tiger Stance is the right choice so either skill maxed is good in different situations.

This might seem like a rant since I'm not experienced in complaining about a champion, but as a Jungle player the most fun times is when Udyr is actually viable but not too strong to overshadow other high damage tanky junglers ( Trundle, Volibear, Shyvana, Skarner, ect.)